1
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Crystallization, X-ray diffraction analysis and structure of ICMP from Pseudomonas aeruginosa. Biochem Biophys Res Commun 2022; 616:129-133. [DOI: 10.1016/j.bbrc.2022.05.083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 05/25/2022] [Indexed: 11/15/2022]
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2
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Zhang X, Yang Q, Shen Q, Zheng J, Jia Z. Identification of a new nucleotide binding site by structural alignment and site directed mutagenesis. Proteins 2018; 86:1140-1146. [PMID: 30168191 DOI: 10.1002/prot.25593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/14/2018] [Accepted: 08/24/2018] [Indexed: 11/12/2022]
Abstract
Nucleotide binding proteins are involved in many important cellular processes and form one of the largest protein families. Traditionally, the identification of nucleotide binding motif, such as the ATP binding P-loop, has relied on the comparison of protein sequences, consideration of the function of each of the proteins and the identification of signature motifs within the sequence. Sometimes, it is difficult to identify nucleotide binding proteins based on sequence alignment because of increased evolutionary distances. In such cases, structural alignments can provide a better guide for comparing specific features of sequences because the overall structures of these motifs are conserved despite low sequence identity. In the present study, on the basis of bioinformatics and structural comparison of three representative protein structures of Ham1 superfamily, YjjX, YggV, and YhdE, previously identified as nucleotide binding proteins, we have identified a novel nucleotide binding motif (T/SXXXXK/R). The importance of this signature motif in binding of nucleotides was validated using site directed mutagenesis. Mutations of conserved residues of the loop either decreased or completely abolished the nucleotide binding activity of the protein. We used the conserved motif identified in the study to search for other proteins having a similar motif. Two proteins, GTP cyclohydrolase II and dephospho-CoA pyrophosphorylase showed presence of the loop, suggesting that this nucleotide binding motif is not unique in the Ham1 superfamily, but represents a novel NTP recognition motif.
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Affiliation(s)
- Xiaoying Zhang
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Qingzhan Yang
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Qingya Shen
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Jimin Zheng
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Zongchao Jia
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
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3
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PDB-wide identification of biological assemblies from conserved quaternary structure geometry. Nat Methods 2017; 15:67-72. [DOI: 10.1038/nmeth.4510] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 10/17/2017] [Indexed: 02/07/2023]
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4
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Shen Q, Tan H, Xing GW, Zheng J, Jia Z. A new method to investigate the catalytic mechanism of YhdE pyrophosphatase by using a pyrophosphate fluorescence probe. Sci Rep 2017; 7:8169. [PMID: 28811554 PMCID: PMC5557916 DOI: 10.1038/s41598-017-08368-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/11/2017] [Indexed: 01/27/2023] Open
Abstract
YhdE is a Maf (multicopy associated filamentation) proteins from Escherichia coli which exhibits pyrophosphatase activity towards selected nucleotides, although its catalytic mechanism remains unclear. Herein we used a novel fluorescence probe (4-isoACBA–Zn(II) complex) to characterize the enzymatic properties of YhdE and its mutant, establishing a new method for assaying pyrophosphatase catalytic function. Our results reveal for the first time that the new fluorescence sensor confers high sensitivity and specificity and pyrophosphate (PPi) is the direct catalytic product of YhdE. Crystal structures of a mutant in the active-site loop (YhdE_E33A) show conformational flexibility implicated in the catalytic mechanism of YhdE. ITC experiments and computational docking further reveal that Asp70 and substrate dTTP coordinate Mn2+. Quantum mechanics calculations indicate that YhdE hydrolysis appears to follow a stepwise pathway in which a water molecule first attacks the α-phosphorus atom in the substrate, followed by the release of PPi from the pentavalent intermediate.
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Affiliation(s)
- Qingya Shen
- College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Hongwei Tan
- College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Guo-Wen Xing
- College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Jimin Zheng
- College of Chemistry, Beijing Normal University, Beijing, 100875, China.
| | - Zongchao Jia
- Department of Biochemical and Molecular Science, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
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5
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Wang N, Jiang J, Li X, Tan H, Zheng J, Chen G, Jia Z. Molecular Dynamics Simulation Studies of dTTP Binding and Catalysis Mediated by YhdE Dimerization. PLoS One 2015; 10:e0134879. [PMID: 26252214 PMCID: PMC4529217 DOI: 10.1371/journal.pone.0134879] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/14/2015] [Indexed: 11/18/2022] Open
Abstract
YhdE is a Maf-like (multicopy associated filamentation) protein that primarily acts as dTTPase to hydrolyze dTTP into dTMP and two phosphate molecules in cell metabolism pathway. Two crystal structures of YhdE have been previously determined, representing the open and closed active site conformations, respectively. Based on the structures, we have carried out molecular dynamics simulations and free energy calculations to investigate dTTP binding to and hydrolysis by YhdE. Our results suggest that YhdE closed state is structurally more compact than its open state at room temperature. YhdE open state is a favorable conformation for dTTP binding and closed state is a structurally favorable conformation for catalytic reaction. This observation is supported by the structure of YhdE homolog in complex with a nucleotide analog. Free energy calculations reveal that YhdE dimerization occurs preferentially in dTTP binding and is favorable for successive cooperative reaction. The key residues R11, R12 and K80, are found to contribute to the substrate stabilization. Further, YhdE dimerization and binding of dTTP induce the cooperative effect through a direct allosteric communication network in YhdE from the dTTP binding sites in the catalytic center to the intermolecular β-strand in YhdE dimer.
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Affiliation(s)
- Nan Wang
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Jiahong Jiang
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Xichen Li
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Hongwei Tan
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Jimin Zheng
- College of Chemistry, Beijing Normal University, Beijing, China
- * E-mail: (JMZ); (ZCJ)
| | - Guangju Chen
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Zongchao Jia
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
- * E-mail: (JMZ); (ZCJ)
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6
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Crystal structure of the MazG-related nucleoside triphosphate pyrophosphohydrolase from Thermotoga maritima MSB8. ACTA ACUST UNITED AC 2015; 16:81-9. [PMID: 25758186 DOI: 10.1007/s10969-015-9195-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/17/2015] [Indexed: 10/23/2022]
Abstract
The MazG family proteins, which are highly conserved in bacteria, are nucleoside triphosphate pyrophosphohydrolases that hydrolyze all canonical nucleoside triphosphates, and are also involved in removing noncanonical nucleoside triphosphates to prevent their incorporation into DNA or RNA. The primary structure of TM0360 from Thermotoga maritima MSB8 suggested that TM0360 is a MazG-related nucleoside triphosphate pyrophosphohydrolase. The crystal structure of the TM0360 protein was determined by the MAD technique at 2.0 Å resolution. The asymmetric unit contains an intact dimer molecule. The overall structure of TM0360 is similar to the known structures of the dimeric MazG protein and dUTPases. The putative NTP binding pocket in TM0360, identified by considering the probable NTP-interacting residues and structural features, suggested that TM0360 resembles the C-terminal domain of Escherichia coli MazG, although TM0360 may be a truncated paralog of the N-terminal domain of T. maritima MazG (TM0913), according to its primary structure. The putative function of TM0360 is discussed, based on structural homology.
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7
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Jin J, Wu R, Zhu J, Yang S, Lei Z, Wang N, Singh VK, Zheng J, Jia Z. Insights into the cellular function of YhdE, a nucleotide pyrophosphatase from Escherichia coli. PLoS One 2015; 10:e0117823. [PMID: 25658941 PMCID: PMC4319933 DOI: 10.1371/journal.pone.0117823] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 01/02/2015] [Indexed: 11/19/2022] Open
Abstract
YhdE, a Maf-like protein in Escherichia coli, exhibits nucleotide pyrophosphatase (PPase) activity, yet its cellular function remains unknown. Here, we characterized the PPase activity of YhdE on dTTP, UTP and TTP and determined two crystal structures of YhdE, revealing ‘closed’ and ‘open’ conformations of an adaptive active site. Our functional studies demonstrated that YhdE retards cell growth by prolonging the lag and log phases, particularly under stress conditions. Morphology studies showed that yhdE-knockout cells transformed the normal rod shape of wild-type cells to a more spherical form, and the cell wall appeared to become more flexible. In contrast, YhdE overexpression resulted in filamentous cells. This study reveals the previously unknown involvement of YhdE in cell growth inhibition under stress conditions, cell-division arrest and cell-shape maintenance, highlighting YhdE’s important role in E. coli cell-cycle checkpoints.
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Affiliation(s)
- Jin Jin
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Ruijuan Wu
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Jia Zhu
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Shaoyuan Yang
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Zhen Lei
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Nan Wang
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Vinay K. Singh
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
| | - Jimin Zheng
- College of Chemistry, Beijing Normal University, Beijing, China
- * E-mail: (JZ); (ZJ)
| | - Zongchao Jia
- College of Chemistry, Beijing Normal University, Beijing, China
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
- * E-mail: (JZ); (ZJ)
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8
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Nagy GN, Leveles I, Vértessy BG. Preventive DNA repair by sanitizing the cellular (deoxy)nucleoside triphosphate pool. FEBS J 2014; 281:4207-23. [PMID: 25052017 DOI: 10.1111/febs.12941] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 07/01/2014] [Accepted: 07/16/2014] [Indexed: 01/24/2023]
Abstract
The occurrence of modified bases in DNA is attributed to some major factors: incorporation of altered nucleotide building blocks and chemical reactions or radiation effects on bases within the DNA structure. Several enzyme families are involved in preventing the incorporation of noncanonical bases playing a 'sanitizing' role. The catalytic mechanism of action of these enzymes has been revealed for a number of representatives in clear structural and kinetic detail. In this review, we focus in detail on those examples where clear evidence has been produced using high-resolution structural studies. Comparing the protein fold and architecture of the enzyme active sites, two main classes of sanitizing deoxyribonucleoside triphosphate pyrophosphatases can be assigned that are distinguished by the site of nucleophilic attack. In enzymes associated with attack at the α-phosphorus, it is shown that coordination of the γ-phosphate group is also ensured by multiple interactions. By contrast, enzymes catalyzing attack at the β-phosphorus atom mainly coordinate the α- and the β-phosphate only. Characteristic differences are also observed with respect to the role of the metal ion cofactor (Mg(2+) ) and the coordination of nucleophilic water. Using different catalytic mechanisms embedded in different protein folds, these enzymes present a clear example of convergent evolution.
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Affiliation(s)
- Gergely N Nagy
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Hungary
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9
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Tchigvintsev A, Tchigvintsev D, Flick R, Popovic A, Dong A, Xu X, Brown G, Lu W, Wu H, Cui H, Dombrowski L, Joo JC, Beloglazova N, Min J, Savchenko A, Caudy AA, Rabinowitz JD, Murzin AG, Yakunin AF. Biochemical and structural studies of conserved Maf proteins revealed nucleotide pyrophosphatases with a preference for modified nucleotides. ACTA ACUST UNITED AC 2013; 20:1386-98. [PMID: 24210219 PMCID: PMC3899018 DOI: 10.1016/j.chembiol.2013.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/06/2013] [Accepted: 09/13/2013] [Indexed: 11/17/2022]
Abstract
Maf (for multicopy associated filamentation) proteins represent a large family of conserved proteins implicated in cell division arrest but whose biochemical activity remains unknown. Here, we show that the prokaryotic and eukaryotic Maf proteins exhibit nucleotide pyrophosphatase activity against 5-methyl-UTP, pseudo-UTP, 5-methyl-CTP, and 7-methyl-GTP, which represent the most abundant modified bases in all organisms, as well as against canonical nucleotides dTTP, UTP, and CTP. Overexpression of the Maf protein YhdE in E. coli cells increased intracellular levels of dTMP and UMP, confirming that dTTP and UTP are the in vivo substrates of this protein. Crystal structures and site-directed mutagenesis of Maf proteins revealed the determinants of their activity and substrate specificity. Thus, pyrophosphatase activity of Maf proteins toward canonical and modified nucleotides might provide the molecular mechanism for a dual role of these proteins in cell division arrest and house cleaning. Maf proteins represent a family of nucleoside triphosphate pyrophosphatases Maf proteins hydrolyze the canonical nucleotides dTTP, UTP, and CTP Maf proteins are also active against m5UTP, m5CTP, pseudo-UTP, and m7GTP Maf structures reveal the molecular mechanisms of their substrate selectivity
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Affiliation(s)
- Anatoli Tchigvintsev
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada
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10
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Awwad K, Desai A, Smith C, Sommerhalter M. Structural and functional characterization of a noncanonical nucleoside triphosphate pyrophosphatase from Thermotoga maritima. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:184-93. [PMID: 23385455 PMCID: PMC3565439 DOI: 10.1107/s0907444912044630] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 10/29/2012] [Indexed: 11/11/2022]
Abstract
The hyperthermophilic bacterium Thermotoga maritima has a noncanonical nucleoside triphosphatase that catalyzes the conversion of inosine triphosphate (ITP), deoxyinosine triphosphate (dITP) and xanthosine triphosphate (XTP) into inosine monophosphate (IMP), deoxyinosine monophosphate (IMP) and xanthosine monophosphate (XMP), respectively. The k(cat)/K(m) values determined at 323 and 353 K fall between 1.31 × 10(4) and 7.80 × 10(4) M(-1) s(-1). ITP and dITP are slightly preferred over XTP. Activity towards canonical nucleoside triphosphates (ATP and GTP) was not detected. The enzyme has an absolute requirement for Mg(2+) as a cofactor and has a preference for alkaline conditions. A protein X-ray structure of the enzyme with bound IMP was obtained at 2.15 Å resolution. The active site houses a well conserved network of residues that are critical for substrate recognition and catalysis. The crystal structure shows a tetramer with two possible dimer interfaces. One of these interfaces strongly resembles the dimer interface that is found in the structures of other noncanonical nucleoside pyrophosphatases from human (human ITPase) and archaea (Mj0226 and PhNTPase).
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Affiliation(s)
- Khaldeyah Awwad
- Chemistry and Biochemistry, California State University East Bay, 25800 Carlos Bee Boulevard, Hayward, CA 94542, USA
| | - Anna Desai
- Chemistry and Biochemistry, California State University East Bay, 25800 Carlos Bee Boulevard, Hayward, CA 94542, USA
| | - Clyde Smith
- Stanford Synchrotron Radiation Lightsource, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Monika Sommerhalter
- Chemistry and Biochemistry, California State University East Bay, 25800 Carlos Bee Boulevard, Hayward, CA 94542, USA
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11
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Briley K, Prepiak P, Dias MJ, Hahn J, Dubnau D. Maf acts downstream of ComGA to arrest cell division in competent cells of B. subtilis. Mol Microbiol 2011; 81:23-39. [PMID: 21564336 DOI: 10.1111/j.1365-2958.2011.07695.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Transformable (competent) cells of Bacillus subtilis are blocked in cell division because the traffic ATPase ComGA prevents the formation of FtsZ rings. Although ComGA-deficient cells elongate and form FtsZ rings, cell division remains blocked at a later stage and the cells become mildly filamented. Here we show that the highly conserved protein Maf is synthesized predominantly in competent cells under the direct control of the transcription factor ComK and is solely responsible for the later block in cell division. In vivo and in vitro data show that Maf binds to both ComGA and DivIVA. A point mutation in maf that interferes with Maf binding to DivIVA also interferes with the ability of Maf to inhibit cell division. Based on these findings, we propose that Maf and ComGA mediate mechanisms for the inhibition of cell division in competent cells with Maf acting downstream of ComGA. We further suggest that Maf must interact with DivIVA to inhibit cell division.
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Affiliation(s)
- Kenneth Briley
- Department of Microbiology and Molecular Genetics, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA
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12
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Abstract
Activation of DNA repair proteins is often accompanied by an arrest in cell division. Several proteins have been identified that regulate the division blockage associated with the SOS response. When Bacillus subtilis cells become genetically competent they also activate DNA repair proteins and stop dividing. In this issue of Molecular Microbiology, Briley et al., 2011 describe a new protein involved in this process. This protein, Maf, does not prevent FtsZ polymerization, but it inhibits synthesis of the division septum. What is fascinating about Maf is that it is conserved and can be found in all kingdoms of life.
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Affiliation(s)
- Leendert W Hamoen
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle NE2 4AX, UK.
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13
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Using correlated parameters for improved ranking of protein-protein docking decoys. J Comput Chem 2010; 32:787-96. [DOI: 10.1002/jcc.21657] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 07/06/2010] [Accepted: 08/06/2010] [Indexed: 11/07/2022]
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14
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Han GW, Elsliger MA, Yeates TO, Xu Q, Murzin AG, Krishna SS, Jaroszewski L, Abdubek P, Astakhova T, Axelrod HL, Carlton D, Chen C, Chiu HJ, Clayton T, Das D, Deller MC, Duan L, Ernst D, Feuerhelm J, Grant JC, Grzechnik A, Jin KK, Johnson HA, Klock HE, Knuth MW, Kozbial P, Kumar A, Lam WW, Marciano D, McMullan D, Miller MD, Morse AT, Nigoghossian E, Okach L, Reyes R, Rife CL, Sefcovic N, Tien HJ, Trame CB, van den Bedem H, Weekes D, Hodgson KO, Wooley J, Deacon AM, Godzik A, Lesley SA, Wilson IA. Structure of a putative NTP pyrophosphohydrolase: YP_001813558.1 from Exiguobacterium sibiricum 255-15. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:1237-44. [PMID: 20944217 PMCID: PMC2954211 DOI: 10.1107/s1744309110025534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 06/29/2010] [Indexed: 11/24/2022]
Abstract
The crystal structure of a putative NTPase, YP_001813558.1 from Exiguobacterium sibiricum 255-15 (PF09934, DUF2166) was determined to 1.78 Å resolution. YP_001813558.1 and its homologs (dimeric dUTPases, MazG proteins and HisE-encoded phosphoribosyl ATP pyrophosphohydrolases) form a superfamily of all-α-helical NTP pyrophosphatases. In dimeric dUTPase-like proteins, a central four-helix bundle forms the active site. However, in YP_001813558.1, an unexpected intertwined swapping of two of the helices that compose the conserved helix bundle results in a `linked dimer' that has not previously been observed for this family. Interestingly, despite this novel mode of dimerization, the metal-binding site for divalent cations, such as magnesium, that are essential for NTPase activity is still conserved. Furthermore, the active-site residues that are involved in sugar binding of the NTPs are also conserved when compared with other α-helical NTPases, but those that recognize the nucleotide bases are not conserved, suggesting a different substrate specificity.
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Affiliation(s)
- Gye Won Han
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Marc-André Elsliger
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Todd O. Yeates
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Qingping Xu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Alexey G. Murzin
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, England
| | - S. Sri Krishna
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
- Program on Bioinformatics and Systems Biology, Sanford–Burnham Medical Research Institute, La Jolla, CA, USA
| | - Lukasz Jaroszewski
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
- Program on Bioinformatics and Systems Biology, Sanford–Burnham Medical Research Institute, La Jolla, CA, USA
| | - Polat Abdubek
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Tamara Astakhova
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Herbert L. Axelrod
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dennis Carlton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Connie Chen
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Hsiu-Ju Chiu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Thomas Clayton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Debanu Das
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Marc C. Deller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lian Duan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Dustin Ernst
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Julie Feuerhelm
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Joanna C. Grant
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Anna Grzechnik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Kevin K. Jin
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Hope A. Johnson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Heath E. Klock
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Mark W. Knuth
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Piotr Kozbial
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Sanford–Burnham Medical Research Institute, La Jolla, CA, USA
| | - Abhinav Kumar
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Winnie W. Lam
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - David Marciano
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Daniel McMullan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Mitchell D. Miller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Andrew T. Morse
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Edward Nigoghossian
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Linda Okach
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Ron Reyes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Christopher L. Rife
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Natasha Sefcovic
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Sanford–Burnham Medical Research Institute, La Jolla, CA, USA
| | - Henry J. Tien
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Christine B. Trame
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Henry van den Bedem
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dana Weekes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Sanford–Burnham Medical Research Institute, La Jolla, CA, USA
| | - Keith O. Hodgson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Photon Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - John Wooley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Ashley M. Deacon
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Adam Godzik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
- Program on Bioinformatics and Systems Biology, Sanford–Burnham Medical Research Institute, La Jolla, CA, USA
| | - Scott A. Lesley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Ian A. Wilson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
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15
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Demirev AV, Khanal A, Sedai BR, Lim SK, Na MK, Nam DH. The role of acyl-coenzyme A carboxylase complex in lipstatin biosynthesis of Streptomyces toxytricini. Appl Microbiol Biotechnol 2010; 87:1129-39. [PMID: 20437235 PMCID: PMC2886142 DOI: 10.1007/s00253-010-2587-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 03/23/2010] [Accepted: 03/24/2010] [Indexed: 11/30/2022]
Abstract
Streptomyces toxytricini produces lipstatin, a specific inhibitor of pancreatic lipase, which is derived from two fatty acid moieties with eight and 14 carbon atoms. The pccB gene locus in 10.6 kb fragment of S. toxytricini chromosomal DNA contains three genes for acyl-coenzyme A carboxylase (ACCase) complex accA3, pccB, and pccE that are presumed to be involved in secondary metabolism. The pccB gene encoding a β subunit of ACCase [carboxyltransferase (CT)] was identified upstream of pccE gene for a small protein of ε subunit. The accA3 encoding the α subunit of ACCase [biotin carboxylase (BC)] was also identified downstream of pccB gene. When the pccB and pccE genes were inactivated by homologous recombination, the lipstatin production was reduced as much as 80%. In contrast, the accumulation of another compound, tetradeca-5.8-dienoic acid (the major lipstatin precursor), was 4.5-fold increased in disruptant compared with wild-type. It implies that PccB of S. toxytricini is involved in the activation of octanoic acid to hexylmalonic acid for lipstatin biosynthesis.
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Affiliation(s)
| | - Anamika Khanal
- Faculty of Pharmacy, Yeungnam University, Gyongsan, 712-749 Korea
| | - Bhishma R. Sedai
- Faculty of Pharmacy, Yeungnam University, Gyongsan, 712-749 Korea
| | - Si Kyu Lim
- GenoTech Corporation, Daejeon, 305-343 Korea
| | - Min Kyun Na
- Faculty of Pharmacy, Yeungnam University, Gyongsan, 712-749 Korea
| | - Doo Hyun Nam
- Faculty of Pharmacy, Yeungnam University, Gyongsan, 712-749 Korea
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16
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Tsuchiya Y, Nakamura H, Kinoshita K. Discrimination between biological interfaces and crystal-packing contacts. Adv Appl Bioinform Chem 2008; 1:99-113. [PMID: 21918609 PMCID: PMC3169932 DOI: 10.2147/aabc.s4255] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A discrimination method between biologically relevant interfaces and artificial crystal-packing contacts in crystal structures was constructed. The method evaluates protein-protein interfaces in terms of complementarities for hydrophobicity, electrostatic potential and shape on the protein surfaces, and chooses the most probable biological interfaces among all possible contacts in the crystal. The method uses a discriminator named as "COMP", which is a linear combination of the complementarities for the above three surface features and does not correlate with the contact area. The discrimination of homo-dimer interfaces from symmetry-related crystal-packing contacts based on the COMP value achieved the modest success rate. Subsequent detailed review of the discrimination results raised the success rate to about 88.8%. In addition, our discrimination method yielded some clues for understanding the interaction patterns in several examples in the PDB. Thus, the COMP discriminator can also be used as an indicator of the "biological-ness" of protein-protein interfaces.
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Affiliation(s)
- Yuko Tsuchiya
- Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minatoku, Tokyo, 108-8639, Japan
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17
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Savchenko A, Proudfoot M, Skarina T, Singer A, Litvinova O, Sanishvili R, Brown G, Chirgadze N, Yakunin AF. Molecular basis of the antimutagenic activity of the house-cleaning inosine triphosphate pyrophosphatase RdgB from Escherichia coli. J Mol Biol 2007; 374:1091-103. [PMID: 17976651 DOI: 10.1016/j.jmb.2007.10.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 10/03/2007] [Accepted: 10/04/2007] [Indexed: 11/17/2022]
Abstract
Inosine triphosphate pyrophosphatases, which are ubiquitous house-cleaning enzymes, hydrolyze noncanonical nucleoside triphosphates (inosine triphosphate (ITP) and xanthosine triphosphate (XTP)) and prevent the incorporation of hypoxanthine or xanthine into nascent DNA or RNA. Here we present the 1.5-A-resolution crystal structure of the inosine triphosphate pyrophosphatase RdgB from Escherichia coli in a free state and in complex with a substrate (ITP+Ca(2+)) or a product (inosine monophosphate (IMP)). ITP binding to RdgB induced a large displacement of the alpha1 helix, closing the enzyme active site. This positions the conserved Lys13 close to the bridging oxygen between the alpha- and beta-phosphates of the substrate, weakening the P(alpha)-O bond. On the other side of the substrate, the conserved Asp69 is proposed to act as a base coordinating the catalytic water molecule. Our data provide insight into the molecular mechanisms of the substrate selectivity and catalysis of RdgB and other ITPases.
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Affiliation(s)
- Alexei Savchenko
- Banting and Best Department of Medical Research and Ontario Center for Structural Proteomics, University of Toronto, 112 College Street, Toronto, Ontario, Canada M5G 1L6
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18
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Chakrabarti S, Bryant SH, Panchenko AR. Functional specificity lies within the properties and evolutionary changes of amino acids. J Mol Biol 2007; 373:801-10. [PMID: 17868687 PMCID: PMC2605514 DOI: 10.1016/j.jmb.2007.08.036] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 07/03/2007] [Accepted: 08/16/2007] [Indexed: 10/22/2022]
Abstract
The rapid increase in the amount of protein sequence data has created a need for automated identification of sites that determine functional specificity among related subfamilies of proteins. A significant fraction of subfamily specific sites are only marginally conserved, which makes it extremely challenging to detect those amino acid changes that lead to functional diversification. To address this critical problem we developed a method named SPEER (specificity prediction using amino acids' properties, entropy and evolution rate) to distinguish specificity determining sites from others. SPEER encodes the conservation patterns of amino acid types using their physico-chemical properties and the heterogeneity of evolutionary changes between and within the subfamilies. To test the method, we compiled a test set containing 13 protein families with known specificity determining sites. Extensive benchmarking by comparing the performance of SPEER with other specificity site prediction algorithms has shown that it performs better in predicting several categories of subfamily specific sites.
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Affiliation(s)
- Saikat Chakrabarti
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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19
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Adams MA, Suits MDL, Zheng J, Jia Z. Piecing together the structure–function puzzle: Experiences in structure-based functional annotation of hypothetical proteins. Proteomics 2007; 7:2920-32. [PMID: 17639604 DOI: 10.1002/pmic.200700099] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The combination of genomic sequencing with structural genomics has provided a wealth of new structures for previously uncharacterized ORFs, more commonly referred to as hypothetical proteins. This rapid growth has been the direct result of high-throughput, automated approaches in both the identification of new ORFs and the determination of high-resolution 3-D protein structures. A significant bottleneck is reached, however, at the stage of functional annotation in that the assignment of function is not readily automatable. It is often the case that the initial structural analysis at best indicates a functional family for a given hypothetical protein, but further identification of a relevant ligand or substrate is impeded by the diversity of function in a particular structural classification of proteins family, a highly selective and specific ligand-binding site, or the identification of a novel protein fold. Our approach to the functional annotation of hypothetical proteins relies on the combination of structural information with additional bioinformatics evidence garnered from operon prediction, loose functional information of additional operon members, conservation of catalytic residues, as well as cocrystallization trials and virtual ligand screening. The synthesis of all available information for each protein has permitted the functional annotation of several hypothetical proteins from Escherichia coli and each assignment has been confirmed through generally accepted biochemical methods.
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Affiliation(s)
- Melanie A Adams
- Department of Biochemistry, Queen's University, Kingston, ON, Canada
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20
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Wu B, Liu Y, Zhao Q, Liao S, Zhang J, Bartlam M, Chen W, Rao Z. Crystal Structure of RS21-C6, Involved in Nucleoside Triphosphate Pyrophosphohydrolysis. J Mol Biol 2007; 367:1405-12. [PMID: 17320107 DOI: 10.1016/j.jmb.2007.01.057] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Revised: 01/19/2007] [Accepted: 01/22/2007] [Indexed: 11/29/2022]
Abstract
RS21-C6, which is highly expressed in all vertebrate genomes and green plants, is proposed to have nucleoside triphosphate pyrophosphohydrolase activity. Here, we report the crystal structures of the core fragment of RS21-C6, named RSCUT, and the complex with the substrate 5-methyl dCTP. The refined structure of RSCUT consists mainly of alpha-helices and shows formation of a tightly associated tetramer. On the basis of the structure of the RSCUT-m5dCTP complex and the results of pyrophosphatase activity assays, several key residues involved in the substrate binding of RS21-C6 have been identified. Tetramer formation is shown to be required for substrate binding.
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Affiliation(s)
- Beili Wu
- Tsinghua-IBP-Nankai Joint Research Group for Structural Biology, Tsinghua University, Beijing 100084, China
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21
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Ni S, Forouhar F, Bussiere DE, Robinson H, Kennedy MA. Crystal structure of VC0702 at 2.0 A: conserved hypothetical protein from Vibrio cholerae. Proteins 2006; 63:733-41. [PMID: 16498616 DOI: 10.1002/prot.20919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
VC0702, a conserved hypothetical protein of unknown function from Vibrio cholerae, resides in a three-gene operon containing the MbaA gene that encodes for a GGDEF and EAL domain-containing protein which is involved in regulating formation of the extracellular matrix of biofilms in Vibrio cholerae. The VC0702 crystal structure has been determined at 2.0 A and refined to Rwork = 22.8% and Rfree = 26.3%. VC0702 crystallized in an orthorhombic crystal lattice in the C222(1) space group with dimensions of a = 66.61 A, b = 88.118 A, and c = 118.35 A with a homodimer in the asymmetric unit. VC0702, which forms a mixed alpha + beta three-layered alphabetaalpha sandwich, belongs to the Pfam DUF84 and COG1986 families of proteins. Sequence conservation within the DUF84 and COG1986 families was used to identify a conserved patch of surface residues that define a cleft and potential substrate-binding site in VC0702. The three-dimensional structure of VC0702 is similar to that of Mj0226 from Methanococcus janeschii, which has been identified as a novel NTPase that binds NTP in a deep cleft similarly located to the conserved patch of surface residues that define an analogous cleft in VC0702. Collectively, the data suggest that VC0702 may have a biochemical function that involves NTP binding and phosphatase activity of some kind, and is likely involved in regulation of the signaling pathway that controls biofilm formation and maintenance in Vibrio cholerae.
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Affiliation(s)
- Shuisong Ni
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
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22
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Abstract
Cellular metabolism constantly generates by-products that are wasteful or even harmful. Such compounds are excreted from the cell or are removed through hydrolysis to normal cellular metabolites by various 'house-cleaning' enzymes. Some of the most important contaminants are non-canonical nucleoside triphosphates (NTPs) whose incorporation into the nascent DNA leads to increased mutagenesis and DNA damage. Enzymes intercepting abnormal NTPs from incorporation by DNA polymerases work in parallel with DNA repair enzymes that remove lesions produced by modified nucleotides. House-cleaning NTP pyrophosphatases targeting non-canonical NTPs belong to at least four structural superfamilies: MutT-related (Nudix) hydrolases, dUTPase, ITPase (Maf/HAM1) and all-alpha NTP pyrophosphatases (MazG). These enzymes have high affinity (Km's in the micromolar range) for their natural substrates (8-oxo-dGTP, dUTP, dITP, 2-oxo-dATP), which allows them to select these substrates from a mixture containing a approximately 1000-fold excess of canonical NTPs. To date, many house-cleaning NTPases have been identified only on the basis of their side activity towards canonical NTPs and NDP derivatives. Integration of growing structural and biochemical data on these superfamilies suggests that their new family members cleanse the nucleotide pool of the products of oxidative damage and inappropriate methylation. House-cleaning enzymes, such as 6-phosphogluconolactonase, are also part of normal intermediary metabolism. Genomic data suggest that house-cleaning systems are more abundant than previously thought and include numerous analogous enzymes with overlapping functions. We discuss the structural diversity of these enzymes, their phylogenetic distribution, substrate specificity and the problem of identifying their true substrates.
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Affiliation(s)
- Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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23
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Rao Z. YjjX: from structure "Tu" function. Structure 2006; 13:1401-2. [PMID: 16216571 DOI: 10.1016/j.str.2005.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It has been shown by structural analysis that YjjX, a hypothetical protein in E. coli, is an ITPase/XTPase and suggest that it may play dual roles in prokaryotic translational regulation and oxidative cell stress response.
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Affiliation(s)
- Zihe Rao
- National Laboratory of Biomacromolecules, Institute of Biophysics (IBP), Chinese Academy of Sciences, Beijing 100101, China
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24
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Zheng J, Singh VK, Jia Z. Identification of an ITPase/XTPase in Escherichia coli by structural and biochemical analysis. Structure 2005; 13:1511-20. [PMID: 16216582 DOI: 10.1016/j.str.2005.07.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Revised: 07/14/2005] [Accepted: 07/17/2005] [Indexed: 01/13/2023]
Abstract
Inosine triphosphate (ITP) and xanthosine triphosphate (XTP) are formed upon deamination of ATP and GTP as a result of exposure to chemical mutagens and oxidative damage. Nucleic acid synthesis requires safeguard mechanisms to minimize undesired lethal incorporation of ITP and XTP. Here, we present the crystal structure of YjjX, a protein of hitherto unknown function. The three-dimensional fold of YjjX is similar to those of Mj0226 from Methanococcus janschii, which possesses nucleotidase activity, and of Maf from Bacillus subtilis, which can bind nucleotides. Biochemical analyses of YjjX revealed it to exhibit specific phosphatase activity for inosine and xanthosine triphosphates and have a possible interaction with elongation factor Tu. The enzymatic activity of YjjX as an inosine/xanthosine triphosphatase provides evidence for a plausible protection mechanism by clearing the noncanonical nucleotides from the cell during oxidative stress in E. coli.
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Affiliation(s)
- Jimin Zheng
- Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada
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25
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Venable RM, Delaglio F, Norris SE, Freedberg DI. The utility of residual dipolar couplings in detecting motion in carbohydrates: application to sucrose. Carbohydr Res 2005; 340:863-74. [PMID: 15780252 DOI: 10.1016/j.carres.2005.01.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Accepted: 01/18/2005] [Indexed: 11/17/2022]
Abstract
The solution structure and dynamics of sucrose are examined using a combination of NMR residual dipolar coupling and molecular mechanics force fields. It is found that the alignment tensors of the individual rings are different, and that fitting 35 measured residual dipolar couplings to structures with specific phi, psi values indicates the presence of three major conformations: phi, psi=(120 degrees ,270 degrees), (45 degrees, 300 degrees) and (90 degrees ,180 degrees). Furthermore, fitting two structures simultaneously to the 35 residual dipolar couplings results in a substantial improvement in the fits. The existence of multiple conformations having similar stabilities is a strong indication of motion, due to the interconversion among these states. Results from four molecular mechanics force fields are in general agreement with the experimental results. However, there are major disagreements between force fields. Because fits of residual dipolar couplings to structures are dependent on the force field used to calculate the structures, multiple force fields were used to interpret NMR data. It is demonstrated that the pucker of the fructofuranosyl ring affects the calculated potential energy surface, and the fit to the residual dipolar couplings data. Previously published 13C nuclear relaxation results suggesting that sucrose is rigid are not inconsistent with the present results when motional timescales are considered.
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Affiliation(s)
- Richard M Venable
- Laboratory of Biophysics, Center for Biologics Evaluation and Research, FDA, 1401 Rockville Pike, HFM-419, MD 20852, USA
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26
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Moroz OV, Murzin AG, Makarova KS, Koonin EV, Wilson KS, Galperin MY. Dimeric dUTPases, HisE, and MazG belong to a new superfamily of all-alpha NTP pyrophosphohydrolases with potential "house-cleaning" functions. J Mol Biol 2005; 347:243-55. [PMID: 15740738 DOI: 10.1016/j.jmb.2005.01.030] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2004] [Revised: 01/11/2005] [Accepted: 01/12/2005] [Indexed: 11/16/2022]
Abstract
Structure-guided analysis of the new dimeric dUTPase family revealed its sequence relationship to the phage T4 dCTPase, phosphoribosyl-ATP pyrophosphatase HisE, NTP pyrophosphatase MazG, and several uncharacterized protein families, including the human protein XTP3TPA (RS21-C6), which is overexpressed in embryonic and cancer cells. Comparison with the recently determined structure of a MazG-like protein from Sulfolobus solfataricus supported the unification of these enzymes in one superfamily of all-alpha NTP pyrophosphatases, suggesting that dimeric dUTPases evolved from a tetrameric MazG-like ancestor by gene duplication. Analysis of the structure of the Sulfolobus MazG points to 2-hydroxyadenosine (isoguanosine) triphosphate, a product of oxidative damage of ATP, as the most likely substrate. We predict that uncharacterized members of this superfamily perform "house-cleaning" functions by hydrolyzing abnormal NTPs and are functionally analogous to the structurally unrelated hydrolases of the Nudix superfamily. We outline probable tertiary and quaternary structures of the all-alpha NTP pyrophosphatase superfamily members.
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Affiliation(s)
- Olga V Moroz
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, UK
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27
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Petock JM, Torshin IY, Weber IT, Harrison RW. Analysis of protein structures reveals regions of rare backbone conformation at functional sites. Proteins 2003; 53:872-9. [PMID: 14635129 DOI: 10.1002/prot.10484] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Regions of rare conformation were located in 300 protein crystal structures representing seven major protein folds. A distance matrix algorithm was used to search rapidly for 9-residue fragments of rare backbone conformation using a comparison to a relational database of encoded fragments derived from the database of nonredundant structures. Rare fragments were found in 61% of the analyzed protein structures. Detailed analysis was performed for 78 proteins of different folds. The rare fragments were located near functional sites in 72% of the protein structures. The rare fragments often formed parts of ligand-binding sites (59%), protein-protein interfaces (8%), and domain-domain contacts (5%). Of the remaining structures, 5% had a high average B-factor or high local B-factors. Statistical analysis suggests that the association between ligands and rare regions does not occur by chance alone. The present study is likely to underestimate the number of functional sites, because not all analyzed protein structures contained a ligand. The results suggest that rapid searches for regions with rare local backbone conformations can assist in prediction of functional sites in novel proteins.
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Affiliation(s)
- John M Petock
- Department of Biology, Georgia State University, Atlanta, Georgia 30303, USA
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28
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Stark A, Russell RB. Annotation in three dimensions. PINTS: Patterns in Non-homologous Tertiary Structures. Nucleic Acids Res 2003; 31:3341-4. [PMID: 12824322 PMCID: PMC168913 DOI: 10.1093/nar/gkg506] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The detection of local structural patterns in proteins (e.g. active sites) can provide insights into protein function in the absence of sequence or fold similarity. Methods to detect such similarities are key during structural annotation, for example with results from Structural Genomics initiatives. PINTS (Patterns in Non-homologous Tertiary Structures, http://pints.embl.de) performs database searches for such patterns and most importantly provides a measure of statistical significance for any similarity uncovered. To aid functional annotation of proteins, we allow comparisons of pre-defined patterns against databases of complete structures and of entire structures to databases of particular residues likely to be functionally important.
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29
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Wilds CJ, Pattanayek R, Pan C, Wawrzak Z, Egli M. Selenium-assisted nucleic acid crystallography: use of phosphoroselenoates for MAD phasing of a DNA structure. J Am Chem Soc 2002; 124:14910-6. [PMID: 12475332 DOI: 10.1021/ja021058b] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The combination of synchrotron radiation and a variety of atoms or ions (either covalently attached to the biomolecule prior to crystallization or soaked into crystals) that serve as anomalous scatterers constitutes a powerful tool in the X-ray crystallographer's repertoire of structure determination techniques. Phosphoroselenoates in which one of the nonbridging phosphate oxygens in the backbone is replaced by selenium offer a simplified means for introducing an anomalous scatterer into oligonucleotides by conventional solid-phase synthesis. Unlike other methods that are used to derivatize DNA or RNA by covalent attachment of a heavy atom (i.e., bromine at the C5 position of pyrimidines), tedious synthesis of specialized nucleosides is not required. Introduction of selenium is readily accomplished in solid-phase oligonucleotide synthesis by replacing the standard oxidation agent with a solution of potassium selenocyanide. This results in a diastereomeric mixture of phosphoroselenoates that can be separated by strong anion-exchange HPLC. As a test case, all 10 DNA hexamers of the sequence CGCGCG containing a single phosphoroselenoate linkage (PSe) were prepared. Crystals were grown for a subset of them, and the structure of [d(C(PSe)GCGCG)](2) was determined by the multiwavelength anomalous dispersion technique and refined to 1.1 A resolution.
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Affiliation(s)
- Christopher J Wilds
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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30
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Teplova M, Wilds CJ, Wawrzak Z, Tereshko V, Du Q, Carrasco N, Huang Z, Egli M. Covalent incorporation of selenium into oligonucleotides for X-ray crystal structure determination via MAD: proof of principle. Multiwavelength anomalous dispersion. Biochimie 2002; 84:849-58. [PMID: 12458077 DOI: 10.1016/s0300-9084(02)01440-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Selenium was incorporated into an oligodeoxynucleotide in the form of 2'-methylseleno-uridine (U(Se)). The X-ray crystal structure of the duplex left open bracket d(GCGTA)U(Se)d(ACGC) right open bracket (2) was determined by the multiwavelength anomalous dispersion (MAD) technique and refined to a resolution of 1.3 A, demonstrating that selenium can selectively substitute oxygen in DNA and that the resulting compounds are chemically stable. Since derivatization at the 2'-alpha-position with selenium does not affect the preference of the sugar for the C3'-endo conformation, this strategy is suitable for incorporating selenium into RNA. The availability of selenium-containing nucleic acids for crystallographic phasing offers an attractive alternative to the commonly used halogenated pyrimidines.
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Affiliation(s)
- Marianna Teplova
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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Berka RM, Hahn J, Albano M, Draskovic I, Persuh M, Cui X, Sloma A, Widner W, Dubnau D. Microarray analysis of the Bacillus subtilis K-state: genome-wide expression changes dependent on ComK. Mol Microbiol 2002; 43:1331-45. [PMID: 11918817 DOI: 10.1046/j.1365-2958.2002.02833.x] [Citation(s) in RCA: 188] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Bacillus subtilis, the competence transcription factor ComK activates its own transcription as well as the transcription of genes that encode DNA transport proteins. ComK is expressed in about 10% of the cells in a culture grown to competence. Using DNA microarrays representing approximately 95% of the protein-coding open reading frames in B. subtilis, we compared the expression profiles of wild-type and comK strains, as well as of a mecA mutant (which produces active ComK in all the cells of the population) and a comK mecA double mutant. In these comparisons, we identified at least 165 genes that are upregulated by ComK and relatively few that are downregulated. The use of reporter fusions has confirmed these results for several genes. Many of the ComK-regulated genes are organized in clusters or operons, and 23 of these clusters are preceded by apparent ComK-box promoter motifs. In addition to those required for DNA uptake, other genes that are upregulated in the presence of ComK are probably involved in DNA repair and in the uptake and utilization of nutritional sources. From this and previous work, we conclude that the ComK regulon defines a growth-arrested state, distinct from sporulation, of which competence for genetic transformation is but one notable feature. We suggest that this is a unique adaptation to stress and that it be termed the 'K-state'.
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Abstract
Structural genomics projects aim to provide an experimental or computational three-dimensional model structure for all of the tractable macromolecules that are encoded by complete genomes. To this end, pilot centres worldwide are now exploring the feasibility of large-scale structure determination. Their experimental structures and computational models are expected to yield insight into the molecular function and mechanism of thousands of proteins. The pervasiveness of this information is likely to change the use of structure in molecular biology and biochemistry.
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Affiliation(s)
- S E Brenner
- Department of Plant and Microbial Biology, University of California, 461A Koshland Hall, Berkeley, California 94720-3102, USA.
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Yu L, Gunasekera AH, Mack J, Olejniczak ET, Chovan LE, Ruan X, Towne DL, Lerner CG, Fesik SW. Solution structure and function of a conserved protein SP14.3 encoded by an essential Streptococcus pneumoniae gene. J Mol Biol 2001; 311:593-604. [PMID: 11493012 DOI: 10.1006/jmbi.2001.4894] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Streptococcus pneumoniae is a major human pathogen that causes high mortality and morbidity rates and has developed resistance to many antibiotics. The genome of S. pneumoniae has recently been completely sequenced revealing many genes encoding hypothetical proteins of unknown function. We have found that the gene encoding one such conserved protein, SP14.3, is essential for growth of S. pneumonia. Since it is essential, SP14.3 represents a potential target for drug discovery. Here, we describe the three-dimensional solution structure of SP14.3 as determined by NMR spectroscopy. The structure consists of two domains each with an alpha/beta-fold. The N-terminal domain contains two alpha-helices and a three-stranded beta-sheet, while the C-terminal domain is composed of one alpha-helix and a five-stranded beta-sheet. The N-terminal domain of the protein contains a highly negatively charged surface and resembles the fold of the N-terminal domain of Thermus thermophilus ribosomal protein S3. The C-terminal domain has a protein fold similar to human small nuclear ribonucleoprotein Sm D3 and Haloarcula marismortui ribosomal protein L21E. The two domains of the protein tumble in solution overall as a whole with an overall molecular rotational correlation time (tau(m)) of 12.9 ns at 25 degrees C. The relative orientation of the two domains is not defined by the nuclear Overhauser effect data. Indeed, residual dipolar couplings and the structure calculations indicate that the relative orientation of the two domains is not rigidly oriented with respect to one another in solution.
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Affiliation(s)
- L Yu
- Pharmaceutical Discovery Division, Abbott Park, IL, 60064-6098, USA.
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Abstract
Following the complete genome sequencing of an increasing number of organisms, structural biology is engaging in a systematic approach of high-throughput structure determination called structural genomics to create a complete inventory of protein folds/structures that will help predict functions for all proteins. First results show that structural genomics will be highly effective in finding functional annotations for proteins of unknown function.
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Affiliation(s)
- P R Mittl
- Institute of Biochemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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Teichmann SA, Murzin AG, Chothia C. Determination of protein function, evolution and interactions by structural genomics. Curr Opin Struct Biol 2001; 11:354-63. [PMID: 11406387 DOI: 10.1016/s0959-440x(00)00215-3] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The genome sequencing projects and knowledge of the entire protein repertoires of many organisms have prompted new procedures and techniques for the large-scale determination of protein structure, function and interactions. Recently, new work has been carried out on the determination of the function and evolutionary relationships of proteins by experimental structural genomics, and the discovery of protein-protein interactions by computational structural genomics.
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Affiliation(s)
- S A Teichmann
- Department of Biochemistry and Molecular Biology, University College London, Gower Street, WC1E 6BT, London, UK.
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Teplova M, Tereshko V, Sanishvili R, Joachimiak A, Bushueva T, Anderson WF, Egli M. The structure of the yrdC gene product from Escherichia coli reveals a new fold and suggests a role in RNA binding. Protein Sci 2000; 9:2557-66. [PMID: 11206077 PMCID: PMC2144518 DOI: 10.1110/ps.9.12.2557] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The yrdC family of genes codes for proteins that occur both independently and as a domain in proteins that have been implicated in regulation. An example for the latter case is the sua5 gene from yeast. SuaS was identified as a suppressor of a translation initiation defect in cytochrome c and is required for normal growth in yeast (Na JG, Pinto I, Hampsey M, 1992, Genetics 11:791-801). However, the function of the Sua5 protein remains unknown; Sua5 could act either at the transcriptional or the posttranscriptional levels to compensate for an aberrant translation start codon in the cyc gene. To potentially learn more about the function of YrdC and proteins featuring this domain, the crystal structure of the YrdC protein from Escherichia coli was determined at a resolution of 2.0 A. YrdC adopts a new fold with no obvious similarity to those of other proteins with known three-dimensional (3D) structure. The protein features a large concave surface on one side that exhibits a positive electrostatic potential. The dimensions of this depression, its curvature, and the fact that conserved basic amino acids are located at its floor suggest that YrdC may be a nucleic acid binding protein. An investigation of YrdC's binding affinities for single- and double-stranded RNA and DNA fragments as well as tRNAs demonstrates that YrdC binds preferentially to double-stranded RNA. Our work provides evidence that 3D structures of functionally uncharacterized gene products with unique sequences can yield novel folds and functional insights.
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Affiliation(s)
- M Teplova
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235, USA
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