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Bustad HJ, Christie MS, Laitaoja M, Aarsand AK, Martinez A, Jänis J, Kallio JP. One ring closer to a closure: the crystal structure of the ES 3 hydroxymethylbilane synthase intermediate. FEBS J 2024; 291:510-526. [PMID: 37863644 DOI: 10.1111/febs.16982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/08/2023] [Accepted: 10/17/2023] [Indexed: 10/22/2023]
Abstract
Hydroxymethylbilane synthase (HMBS), involved in haem biosynthesis, catalyses the head-to-tail coupling of four porphobilinogens (PBGs) via a dipyrromethane (DPM) cofactor. DPM is composed of two PBGs, and a hexapyrrole is built before the tetrapyrrolic 1-hydroxymethylbilane product is released. During this elongation, stable enzyme (E) intermediates are formed from the holoenzyme, with additional PBG substrates (S): ES, ES2 , ES3 and ES4 . Native PAGE and mass spectrometry of the acute intermittent porphyria (AIP)-associated HMBS variant p.Arg167Gln demonstrated an increased amount of ES3 . Kinetic parameters indicated catalytic dysfunction, however, the product release was not entirely prevented. Isolation and crystal structure analysis of the ES3 intermediate (PDB: 8PND) showed that a pentapyrrole was fully retained within the active site, revealing that polypyrrole elongation proceeds within the active site via a third interaction site, intermediate pyrrole site 3 (IPS3). The AIP-associated HMBS variant p.Arg195Cys, located on the opposite side to p.Arg167Gln in the active site, accumulated the ES4 intermediate in the presence of excess PBG, implying that product hydrolysis was obstructed. Arg167 is thus involved in all elongation steps and is a determinant for the rate of enzyme catalysis, whereas Arg195 is important for releasing the product. Moreover, by substituting residues in the vicinity of IPS3, our results indicate that a fully retained hexapyrrole could be hydrolysed in a novel site in proximity of the IPS3.
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Affiliation(s)
- Helene J Bustad
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Marthe S Christie
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Mikko Laitaoja
- Department of Chemistry, University of Eastern Finland, Joensuu, Finland
| | - Aasne K Aarsand
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
- Norwegian Organization for Quality Improvement of Laboratory Examinations, Haraldsplass Deaconess Hospital, Bergen, Norway
| | | | - Janne Jänis
- Department of Chemistry, University of Eastern Finland, Joensuu, Finland
| | - Juha P Kallio
- Department of Biomedicine, University of Bergen, Norway
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2
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Christie MS, Laitaoja M, Aarsand AK, Kallio JP, Bustad HJ. Characterisation of a common hotspot variant in acute intermittent porphyria sheds light on the mechanism of hydroxymethylbilane synthase function. FEBS Open Bio 2022; 12:2136-2146. [PMID: 36115019 PMCID: PMC9714363 DOI: 10.1002/2211-5463.13490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/10/2022] [Accepted: 09/16/2022] [Indexed: 01/25/2023] Open
Abstract
Hydroxymethylbilane synthase (HMBS) is the third enzyme involved in haem biosynthesis, in which it catalyses the formation of tetrapyrrole 1-hydroxymethylbilane (HMB). In this process, HMBS binds four consecutive substrate molecules, creating the enzyme-intermediate complexes ES, ES2 , ES3 and ES4 . Pathogenic variants in the HMBS gene are associated with the dominantly inherited disorder acute intermittent porphyria. In this study, we have characterised the p.R26H variant to shed light on the role of Arg26 in the elongation mechanism of HMBS and to provide insights into its effect on the enzyme. With selected biophysical methods, we have been able to show that p.R26H forms a single enzyme-intermediate complex in the ES2 -state. We were also able to demonstrate that the p.R26H variant results in an inactive enzyme, which is unable to produce the HMB product.
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Affiliation(s)
- Marthe S. Christie
- Department of BiomedicineUniversity of BergenNorway,Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and PharmacologyHaukeland University HospitalBergenNorway
| | - Mikko Laitaoja
- Department of ChemistryUniversity of Eastern FinlandJoensuuFinland
| | - Aasne K. Aarsand
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and PharmacologyHaukeland University HospitalBergenNorway,Norwegian Organization for Quality Improvement of Laboratory ExaminationsHaraldsplass Deaconess HospitalBergenNorway
| | | | - Helene J. Bustad
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and PharmacologyHaukeland University HospitalBergenNorway
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3
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Helliwell JR. The crystal structures of the enzyme hydroxymethylbilane synthase, also known as porphobilinogen deaminase. Acta Crystallogr F Struct Biol Commun 2021; 77:388-398. [PMID: 34726177 PMCID: PMC8561815 DOI: 10.1107/s2053230x2100964x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/16/2021] [Indexed: 12/03/2022] Open
Abstract
The enzyme hydroxymethylbilane synthase (HMBS; EC 4.3.1.8), also known as porphobilinogen deaminase, catalyses the stepwise addition of four molecules of porphobilinogen to form the linear tetrapyrrole 1-hydroxymethylbilane. Thirty years of crystal structures are surveyed in this topical review. These crystal structures aim at the elucidation of the structural basis of the complex reaction mechanism involving the formation of tetrapyrrole from individual porphobilinogen units. The consistency between the various structures is assessed. This includes an evaluation of the precision of each molecular model and what was not modelled. A survey is also made of the crystallization conditions used in the context of the operational pH of the enzyme. The combination of 3D structural techniques, seeking accuracy, has also been a feature of this research effort. Thus, SAXS, NMR and computational molecular dynamics have also been applied. The general framework is also a considerable chemistry research effort to understand the function of the enzyme and its medical pathologies in acute intermittent porphyria (AIP). Mutational studies and their impact on the catalytic reaction provide insight into the basis of AIP and are also invaluable for guiding the understanding of the crystal structure results. Future directions for research on HMBS are described, including the need to determine the protonation states of key amino-acid residues identified as being catalytically important. The question remains - what is the molecular engine for this complex reaction? Thermal fluctuations are the only suggestion thus far.
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Affiliation(s)
- John R. Helliwell
- Department of Chemistry, University of Manchester, Manchester M13 9PL, United Kingdom
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4
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Karthikaichamy A, Beardall J, Coppel R, Noronha S, Bulach D, Schittenhelm RB, Srivastava S. Data-Independent-Acquisition-Based Proteomic Approach towards Understanding the Acclimation Strategy of Oleaginous Microalga Microchloropsis gaditana CCMP526 in Hypersaline Conditions. ACS OMEGA 2021; 6:22151-22164. [PMID: 34497906 PMCID: PMC8412934 DOI: 10.1021/acsomega.1c02786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
Salinity is one of the significant factors that affect growth and cellular metabolism, including photosynthesis and lipid accumulation, in microalgae and higher plants. Microchloropsis gaditana CCMP526 can acclimatize to different salinity levels by accumulating compatible solutes, carbohydrates, and lipids as energy storage molecules. We used proteomics to understand the molecular basis for acclimation of M. gaditana to increased salinity levels [55 and 100 PSU (practical salinity unit)]. Correspondence analysis was used for the identification of salinity-responsive proteins (SRPs). The highest number of salinity-induced proteins was observed in 100 PSU. Gene ontology enrichment analysis revealed a separate path of acclimation for cells exposed to 55 and 100 PSU. Osmolyte and lipid biosynthesis were upregulated in hypersaline conditions. Concomitantly, lipid oxidation pathways were also upregulated in hypersaline conditions, providing acetyl-CoA for energy metabolism through the tricarboxylic acid cycle. Carbon fixation and photosynthesis were tightly regulated, while chlorophyll biosynthesis was affected in hypersaline conditions. Importantly, temporal proteome analysis of salinity-induced M. gaditana revealed vital SRPs which could be used for engineering salinity resilient microalgal strains for improved productivity in hypersaline culture conditions.
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Affiliation(s)
- Anbarasu Karthikaichamy
- IITB-Monash
Research Academy, Mumbai 400076, India
- Department
of Microbiology, Monash University, Clayton, 3800 Victoria, Australia
- Department
of Chemical Engineering, IIT Bombay, Mumbai 400076, India
| | - John Beardall
- School
of Biological Sciences, Monash University, Clayton, 3800 Victoria, Australia
| | - Ross Coppel
- Department
of Microbiology, Monash University, Clayton, 3800 Victoria, Australia
| | - Santosh Noronha
- Department
of Chemical Engineering, IIT Bombay, Mumbai 400076, India
| | - Dieter Bulach
- Medicine,
Dentistry and Health Sciences, University
of Melbourne, Melbourne 3010, Australia
| | - Ralf B. Schittenhelm
- Monash Proteomics
& Metabolomics Facility, Monash University, Clayton, 3800 Victoria, Australia
| | - Sanjeeva Srivastava
- Department
of Biosciences and Bioengineering, IIT Bombay, Mumbai 400076, India
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5
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Xue Y, Li X, Mao M, He Y, Owusu Adjei M, Zhou X, Hu H, Liu J, Li X, Ma J. AbhemC encoding porphobilinogen deaminase plays an important role in chlorophyll biosynthesis and function in albino Ananas comosus var. bracteatus leaves. PeerJ 2021; 9:e11118. [PMID: 33850657 PMCID: PMC8018242 DOI: 10.7717/peerj.11118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 02/25/2021] [Indexed: 11/29/2022] Open
Abstract
Background The chimeric leaves of Ananas comosus var. bracteatus are composed of normal green parts (Grs) and albino white parts (Whs). Although the underlying mechanism of albinism in A. comosus var. bracteatus leaves is not fully understood, it is likely associated with the chlorophyll (Chl) biosynthesis. In this biosynthetic process, porphobilinogen deaminase (PBGD) plays a crucial role by catalyzing the conversion of porphobilinogen (PBG) to uroporphyrinogen III (Urogen III). Therefore, its encoding gene AbhemC was investigated here in association with Chl biosynthesis and albinism in chimeric A. comosus var. bracteatus leaves. Methods The Chl content, main Chl biosynthesis precursor content, and main enzyme activity were determined and compared between the Whs and Grs of A. comosus var. bracteatus leaves. In addition, AbhemC was cloned and its transcriptional expression and prokaryotic protein expression were analyzed. Furthermore, RNAi-mediated silencing of AbhemC was produced and assessed in tobacco plants. Results The concentration of Chl a and Chl b in the Grs was significantly higher than that in the Whs, respectively. Additionally, the content of the Chl biosynthesis precursor Urogen III decreased significantly in the Whs compared with the Grs. Thus, the transition of PBG to Urogen III may be the first rate-limiting step leading to albinism in the chimeric leaves of A. comosus var. bracteatus. The gene AbhemC comprised 1,135 bp and was encoded into a protein with 371 amino acids; phylogenetically, AbhemC was most closely related to hemC of pineapple. Prokaryotic expression and in vitro enzyme activity analysis showed that the cloned mRNA sequence of AbhemC was successfully integrated and had PBGD activity. Compared with control plants, transgenic tobacco leaves with pFGC5941-AbhemC-RNAi vector were substantially less green with significantly reduced hemC expression and Chl content, as well as reduced PBGD enzyme activity and significantly decreased content of Chl biosynthesis precursors from Urogen III onwards. Our results suggest that the absence of hemC expression reduces the enzyme activity of PBGD, which blocks the transition of PBG to Urogen III, and in turn suppresses Chl synthesis leading to the pale-green leaf color. Therefore, we suggest that AbhemC plays an important role in Chl synthesis and may be an important factor in the albinism of A. comosus var. bracteatus leaves.
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Affiliation(s)
- Yanbin Xue
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China.,College of Biology and Food Engineering, Chongqing Three Gorges College, Chongqing, China
| | - Xia Li
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Meiqin Mao
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Yehua He
- South China Agricultural University, Guangzhou, China
| | - Mark Owusu Adjei
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Xuzixin Zhou
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Hao Hu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Jiawen Liu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Xi Li
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
| | - Jun Ma
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, China
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6
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Bustad HJ, Kallio JP, Laitaoja M, Toska K, Kursula I, Martinez A, Jänis J. Characterization of porphobilinogen deaminase mutants reveals that arginine-173 is crucial for polypyrrole elongation mechanism. iScience 2021; 24:102152. [PMID: 33665570 PMCID: PMC7907807 DOI: 10.1016/j.isci.2021.102152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/03/2020] [Accepted: 02/02/2021] [Indexed: 11/16/2022] Open
Abstract
Porphobilinogen deaminase (PBGD), the third enzyme in the heme biosynthesis, catalyzes the sequential coupling of four porphobilinogen (PBG) molecules into a heme precursor. Mutations in PBGD are associated with acute intermittent porphyria (AIP), a rare metabolic disorder. We used Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to demonstrate that wild-type PBGD and AIP-associated mutant R167W both existed as holoenzymes (Eholo) covalently attached to the dipyrromethane cofactor, and three intermediate complexes, ES, ES2, and ES3, where S represents PBG. In contrast, only ES2 was detected in AIP-associated mutant R173W, indicating that the formation of ES3 is inhibited. The R173W crystal structure in the ES2-state revealed major rearrangements of the loops around the active site, compared to wild-type PBGD in the Eholo-state. These results contribute to elucidating the structural pathogenesis of two common AIP-associated mutations and reveal the important structural role of Arg173 in the polypyrrole elongation mechanism.
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Affiliation(s)
- Helene J Bustad
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Juha P Kallio
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Mikko Laitaoja
- Department of Chemistry, University of Eastern Finland, 80130 Joensuu, Finland
| | - Karen Toska
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway
| | - Inari Kursula
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway.,Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90570 Oulu, Finland
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Janne Jänis
- Department of Chemistry, University of Eastern Finland, 80130 Joensuu, Finland
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7
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Sato H, Sugishima M, Tsukaguchi M, Masuko T, Iijima M, Takano M, Omata Y, Hirabayashi K, Wada K, Hisaeda Y, Yamamoto K. Crystal structures of hydroxymethylbilane synthase complexed with a substrate analog: a single substrate-binding site for four consecutive condensation steps. Biochem J 2021; 478:1023-1042. [PMID: 33600566 PMCID: PMC7959689 DOI: 10.1042/bcj20200996] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/10/2021] [Accepted: 02/12/2021] [Indexed: 11/30/2022]
Abstract
Hydroxymethylbilane synthase (HMBS), which is involved in the heme biosynthesis pathway, has a dipyrromethane cofactor and combines four porphobilinogen (PBG) molecules to form a linear tetrapyrrole, hydroxymethylbilane. Enzyme kinetic study of human HMBS using a PBG-derivative, 2-iodoporphobilinogen (2-I-PBG), exhibited noncompetitive inhibition with the inhibition constant being 5.4 ± 0.3 µM. To elucidate the reaction mechanism of HMBS in detail, crystal structure analysis of 2-I-PBG-bound holo-HMBS and its reaction intermediate possessing two PBG molecules (ES2), and inhibitor-free ES2 was performed at 2.40, 2.31, and 1.79 Å resolution, respectively. Their overall structures are similar to that of inhibitor-free holo-HMBS, and the differences are limited near the active site. In both 2-I-PBG-bound structures, 2-I-PBG is located near the terminus of the cofactor or the tetrapyrrole chain. The propionate group of 2-I-PBG interacts with the side chain of Arg173, and its acetate group is associated with the side chains of Arg26 and Ser28. Furthermore, the aminomethyl group and pyrrole nitrogen of 2-I-PBG form hydrogen bonds with the side chains of Gln34 and Asp99, respectively. These amino acid residues form a single substrate-binding site, where each of the four PBG molecules covalently binds to the cofactor (or oligopyrrole chain) consecutively, ultimately forming a hexapyrrole chain. Molecular dynamics simulation of the ES2 intermediate suggested that the thermal fluctuation of the lid and cofactor-binding loops causes substrate recruitment and oligopyrrole chain shift needed for consecutive condensation. Finally, the hexapyrrole chain is hydrolyzed self-catalytically to produce hydroxymethylbilane.
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Affiliation(s)
- Hideaki Sato
- Department of Medical Biochemistry, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
| | - Masakazu Sugishima
- Department of Medical Biochemistry, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
| | - Mai Tsukaguchi
- Department of Medical Biochemistry, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
| | - Takahiro Masuko
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Mikuru Iijima
- Department of Pure and Applied Physics, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Mitsunori Takano
- Department of Pure and Applied Physics, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Yoshiaki Omata
- Department of Molecular Biology, Faculty of Pharmaceutical Science, Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama 245-0066, Japan
| | - Kei Hirabayashi
- Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Kei Wada
- Department of Medical Sciences, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan
| | - Yoshio Hisaeda
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ken Yamamoto
- Department of Medical Biochemistry, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
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8
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Bustad HJ, Kallio JP, Vorland M, Fiorentino V, Sandberg S, Schmitt C, Aarsand AK, Martinez A. Acute Intermittent Porphyria: An Overview of Therapy Developments and Future Perspectives Focusing on Stabilisation of HMBS and Proteostasis Regulators. Int J Mol Sci 2021; 22:E675. [PMID: 33445488 PMCID: PMC7827610 DOI: 10.3390/ijms22020675] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/21/2022] Open
Abstract
Acute intermittent porphyria (AIP) is an autosomal dominant inherited disease with low clinical penetrance, caused by mutations in the hydroxymethylbilane synthase (HMBS) gene, which encodes the third enzyme in the haem biosynthesis pathway. In susceptible HMBS mutation carriers, triggering factors such as hormonal changes and commonly used drugs induce an overproduction and accumulation of toxic haem precursors in the liver. Clinically, this presents as acute attacks characterised by severe abdominal pain and a wide array of neurological and psychiatric symptoms, and, in the long-term setting, the development of primary liver cancer, hypertension and kidney failure. Treatment options are few, and therapies preventing the development of symptomatic disease and long-term complications are non-existent. Here, we provide an overview of the disorder and treatments already in use in clinical practice, in addition to other therapies under development or in the pipeline. We also introduce the pathomechanistic effects of HMBS mutations, and present and discuss emerging therapeutic options based on HMBS stabilisation and the regulation of proteostasis. These are novel mechanistic therapeutic approaches with the potential of prophylactic correction of the disease by totally or partially recovering the enzyme functionality. The present scenario appears promising for upcoming patient-tailored interventions in AIP.
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Affiliation(s)
- Helene J. Bustad
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
| | - Juha P. Kallio
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
| | - Marta Vorland
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
| | - Valeria Fiorentino
- INSERM U1149, Center for Research on Inflammation (CRI), Université de Paris, 75018 Paris, France; (V.F.); (C.S.)
| | - Sverre Sandberg
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, 5009 Bergen, Norway
| | - Caroline Schmitt
- INSERM U1149, Center for Research on Inflammation (CRI), Université de Paris, 75018 Paris, France; (V.F.); (C.S.)
- Assistance Publique Hôpitaux de Paris (AP-HP), Centre Français des Porphyries, Hôpital Louis Mourier, 92700 Colombes, France
| | - Aasne K. Aarsand
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, 5009 Bergen, Norway
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
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9
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Mezhuev YO, Korshak YV, Shtilman MI, Pokhil SE. Electronic and Crystal Structures of Nitrogen-Containing Electroconductive and Electroactive Polymers. J STRUCT CHEM+ 2019. [DOI: 10.1134/s0022476619040097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Bung N, Roy A, Priyakumar UD, Bulusu G. Computational modeling of the catalytic mechanism of hydroxymethylbilane synthase. Phys Chem Chem Phys 2019; 21:7932-7940. [DOI: 10.1039/c9cp00196d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hydroxymethylbilane synthase (HMBS), the third enzyme in the heme biosynthesis pathway, catalyzes the formation of 1-hydroxymethylbilane (HMB) by a stepwise polymerization of four molecules of porphobilinogen (PBG) using the dipyrromethane (DPM) cofactor.
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Affiliation(s)
- Navneet Bung
- TCS Innovation Labs – Hyderabad (Life Sciences Division)
- Tata Consultancy Services Limited
- Hyderabad 500081
- India
- Center for Computational Natural Sciences and Bioinformatics
| | - Arijit Roy
- TCS Innovation Labs – Hyderabad (Life Sciences Division)
- Tata Consultancy Services Limited
- Hyderabad 500081
- India
| | - U. Deva Priyakumar
- Center for Computational Natural Sciences and Bioinformatics
- International Institute of Information Technology
- Hyderabad 500032
- India
| | - Gopalakrishnan Bulusu
- TCS Innovation Labs – Hyderabad (Life Sciences Division)
- Tata Consultancy Services Limited
- Hyderabad 500081
- India
- Center for Computational Natural Sciences and Bioinformatics
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11
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Pluta P, Roversi P, Bernardo-Seisdedos G, Rojas AL, Cooper JB, Gu S, Pickersgill RW, Millet O. Structural basis of pyrrole polymerization in human porphobilinogen deaminase. Biochim Biophys Acta Gen Subj 2018; 1862:1948-1955. [PMID: 29908816 DOI: 10.1016/j.bbagen.2018.06.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/17/2018] [Accepted: 06/13/2018] [Indexed: 01/27/2023]
Abstract
Human porphobilinogen deaminase (PBGD), the third enzyme in the heme pathway, catalyzes four times a single reaction to convert porphobilinogen into hydroxymethylbilane. Remarkably, PBGD employs a single active site during the process, with a distinct yet chemically equivalent bond formed each time. The four intermediate complexes of the enzyme have been biochemically validated and they can be isolated but they have never been structurally characterized other than the apo- and holo-enzyme bound to the cofactor. We present crystal structures for two human PBGD intermediates: PBGD loaded with the cofactor and with the reaction intermediate containing two additional substrate pyrrole rings. These results, combined with SAXS and NMR experiments, allow us to propose a mechanism for the reaction progression that requires less structural rearrangements than previously suggested: the enzyme slides a flexible loop over the growing-product active site cavity. The structures and the mechanism proposed for this essential reaction explain how a set of missense mutations result in acute intermittent porphyria.
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Affiliation(s)
- Paula Pluta
- Protein Stability and Inherited Disease Laboratory, CIC bioGUNE, Derio, Bizkaia 48160, Spain
| | - Pietro Roversi
- Oxford Glycobiology Institute, Dept. of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7RH, England, UK
| | | | - Adriana L Rojas
- Structural Biology Unit, CIC bioGUNE, Derio, Bizkaia 48160, Spain
| | - Jonathan B Cooper
- Department of Biological Sciences, Birkbeck, London WC1E 7HX, UK; Division of Medicine, University College London, London WC1E 6BT, UK
| | - Shuang Gu
- School of Biological and Chemical Sciences, Chemistry & Biochemistry Department, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Richard W Pickersgill
- School of Biological and Chemical Sciences, Chemistry & Biochemistry Department, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Oscar Millet
- Protein Stability and Inherited Disease Laboratory, CIC bioGUNE, Derio, Bizkaia 48160, Spain.
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Human hydroxymethylbilane synthase: Molecular dynamics of the pyrrole chain elongation identifies step-specific residues that cause AIP. Proc Natl Acad Sci U S A 2018; 115:E4071-E4080. [PMID: 29632172 DOI: 10.1073/pnas.1719267115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hydroxymethylbilane synthase (HMBS), the third enzyme in the heme biosynthetic pathway, catalyzes the head-to-tail condensation of four molecules of porphobilinogen (PBG) to form the linear tetrapyrrole 1-hydroxymethylbilane (HMB). Mutations in human HMBS (hHMBS) cause acute intermittent porphyria (AIP), an autosomal-dominant disorder characterized by life-threatening neurovisceral attacks. Although the 3D structure of hHMBS has been reported, the mechanism of the stepwise polymerization of four PBG molecules to form HMB remains unknown. Moreover, the specific roles of each of the critical active-site residues in the stepwise enzymatic mechanism and the dynamic behavior of hHMBS during catalysis have not been investigated. Here, we report atomistic studies of HMB stepwise synthesis by using molecular dynamics (MD) simulations, mutagenesis, and in vitro expression analyses. These studies revealed that the hHMBS active-site loop movement and cofactor turn created space for the elongating pyrrole chain. Twenty-seven residues around the active site and water molecules interacted to stabilize the large, negatively charged, elongating polypyrrole. Mutagenesis of these active-site residues altered the binding site, hindered cofactor binding, decreased catalysis, impaired ligand exit, and/or destabilized the enzyme. Based on intermediate stages of chain elongation, R26 and R167 were the strongest candidates for proton transfer to deaminate the incoming PBG molecules. Unbiased random acceleration MD simulations identified R167 as a gatekeeper and facilitator of HMB egress through the space between the enzyme's domains and the active-site loop. These studies identified the specific active-site residues involved in each step of pyrrole elongation, thereby providing the molecular bases of the active-site mutations causing AIP.
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13
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Guo J, Erskine P, Coker AR, Wood SP, Cooper JB. Structural studies of domain movement in active-site mutants of porphobilinogen deaminase from Bacillus megaterium. Acta Crystallogr F Struct Biol Commun 2017; 73:612-620. [PMID: 29095155 PMCID: PMC5683031 DOI: 10.1107/s2053230x17015436] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/23/2017] [Indexed: 11/10/2022] Open
Abstract
The enzyme porphobilinogen deaminase (PBGD) is one of the key enzymes in tetrapyrrole biosynthesis. It catalyses the formation of a linear tetrapyrrole from four molecules of the substrate porphobilinogen (PBG). It has a dipyrromethane cofactor (DPM) in the active site which is covalently linked to a conserved cysteine residue through a thioether bridge. The substrate molecules are linked to the cofactor in a stepwise head-to-tail manner during the reaction, which is catalysed by a conserved aspartate residue: Asp82 in the B. megaterium enzyme. Three mutations have been made affecting Asp82 (D82A, D82E and D82N) and their crystal structures have been determined at resolutions of 2.7, 1.8 and 1.9 Å, respectively. These structures reveal that whilst the D82E mutant possesses the DPM cofactor, in the D82N and D82A mutants the cofactor is likely to be missing, incompletely assembled or disordered. Comparison of the mutant PBGD structures with that of the wild-type enzyme shows that there are significant domain movements and suggests that the enzyme adopts `open' and `closed' conformations, potentially in response to substrate binding.
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Affiliation(s)
- Jingxu Guo
- Division of Medicine, University College London, Gower Street, London WC1E 6BT, England
| | - Peter Erskine
- Division of Medicine, University College London, Gower Street, London WC1E 6BT, England
- Department of Biological Sciences, Birkbeck, University of London, Malet Street, Bloomsbury, London WC1E 7HX, England
| | - Alun R. Coker
- Division of Medicine, University College London, Gower Street, London WC1E 6BT, England
| | - Steve P. Wood
- Division of Medicine, University College London, Gower Street, London WC1E 6BT, England
| | - Jonathan B. Cooper
- Division of Medicine, University College London, Gower Street, London WC1E 6BT, England
- Department of Biological Sciences, Birkbeck, University of London, Malet Street, Bloomsbury, London WC1E 7HX, England
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Dailey HA, Dailey TA, Gerdes S, Jahn D, Jahn M, O'Brian MR, Warren MJ. Prokaryotic Heme Biosynthesis: Multiple Pathways to a Common Essential Product. Microbiol Mol Biol Rev 2017; 81:e00048-16. [PMID: 28123057 PMCID: PMC5312243 DOI: 10.1128/mmbr.00048-16] [Citation(s) in RCA: 191] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The advent of heme during evolution allowed organisms possessing this compound to safely and efficiently carry out a variety of chemical reactions that otherwise were difficult or impossible. While it was long assumed that a single heme biosynthetic pathway existed in nature, over the past decade, it has become clear that there are three distinct pathways among prokaryotes, although all three pathways utilize a common initial core of three enzymes to produce the intermediate uroporphyrinogen III. The most ancient pathway and the only one found in the Archaea converts siroheme to protoheme via an oxygen-independent four-enzyme-step process. Bacteria utilize the initial core pathway but then add one additional common step to produce coproporphyrinogen III. Following this step, Gram-positive organisms oxidize coproporphyrinogen III to coproporphyrin III, insert iron to make coproheme, and finally decarboxylate coproheme to protoheme, whereas Gram-negative bacteria first decarboxylate coproporphyrinogen III to protoporphyrinogen IX and then oxidize this to protoporphyrin IX prior to metal insertion to make protoheme. In order to adapt to oxygen-deficient conditions, two steps in the bacterial pathways have multiple forms to accommodate oxidative reactions in an anaerobic environment. The regulation of these pathways reflects the diversity of bacterial metabolism. This diversity, along with the late recognition that three pathways exist, has significantly slowed advances in this field such that no single organism's heme synthesis pathway regulation is currently completely characterized.
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Affiliation(s)
- Harry A Dailey
- Department of Microbiology, Department of Biochemistry and Molecular Biology, and Biomedical and Health Sciences Institute, University of Georgia, Athens, Georgia, USA
| | - Tamara A Dailey
- Department of Microbiology, Department of Biochemistry and Molecular Biology, and Biomedical and Health Sciences Institute, University of Georgia, Athens, Georgia, USA
| | - Svetlana Gerdes
- Fellowship for Interpretation of Genomes, Burr Ridge, Illinois, USA
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universitaet Braunschweig, Braunschweig, Germany
| | - Martina Jahn
- Institute of Microbiology, Technische Universitaet Braunschweig, Braunschweig, Germany
| | - Mark R O'Brian
- Department of Biochemistry, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Martin J Warren
- Department of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
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Bung N, Pradhan M, Srinivasan H, Bulusu G. Structural insights into E. coli porphobilinogen deaminase during synthesis and exit of 1-hydroxymethylbilane. PLoS Comput Biol 2014; 10:e1003484. [PMID: 24603363 PMCID: PMC3945110 DOI: 10.1371/journal.pcbi.1003484] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 01/08/2014] [Indexed: 11/19/2022] Open
Abstract
Porphobilinogen deaminase (PBGD) catalyzes the formation of 1-hydroxymethylbilane (HMB), a crucial intermediate in tetrapyrrole biosynthesis, through a step-wise polymerization of four molecules of porphobilinogen (PBG), using a unique dipyrromethane (DPM) cofactor. Structural and biochemical studies have suggested residues with catalytic importance, but their specific role in the mechanism and the dynamic behavior of the protein with respect to the growing pyrrole chain remains unknown. Molecular dynamics simulations of the protein through the different stages of pyrrole chain elongation suggested that the compactness of the overall protein decreases progressively with addition of each pyrrole ring. Essential dynamics showed that domains move apart while the cofactor turn region moves towards the second domain, thus creating space for the pyrrole rings added at each stage. Residues of the flexible active site loop play a significant role in its modulation. Steered molecular dynamics was performed to predict the exit mechanism of HMB from PBGD at the end of the catalytic cycle. Based on the force profile and minimal structural changes the proposed path for the exit of HMB is through the space between the domains flanking the active site loop. Residues reported as catalytically important, also play an important role in the exit of HMB. Further, upon removal of HMB, the structure of PBGD gradually relaxes to resemble its initial stage structure, indicating its readiness to resume a new catalytic cycle. Heme is the prosthetic group at the core of the oxygen carrier metalloprotein hemoglobin. Heme consists of a tetrapyrrole called porphyrin bound to an iron ion. It is synthesized by the heme biosynthetic pathway, which is common to all eukaryotes and most prokaryotes. Porphobilinogen deaminase, an enzyme in the heme biosynthetic pathway, catalyzes the formation of a linear tetrapyrrole product, 1-hydroxymethylbilane, from four units of porphobilinogen. In this study we carried out molecular dynamics simulations to understand the structural changes that the enzyme undergoes while catalyzing this reaction. There are three segments to the study: 1) understanding the changes in the enzyme when the porphobilinogen units get attached to the dipyrromethane cofactor, thereby forming a polypyrrole chain; 2) exit of the product from the active site of the enzyme via steered molecular dynamics; and 3) the relaxation of the enzyme to the initial stage to resume its catalytic cycle. Molecular dynamics simulations of the protein through the different stages of pyrrole chain elongation gives insight into the motions of domains, active site loop and role of conserved active site residues in facilitating the accommodation of the polypyrrole chain. In addition to this, we propose a possible exit path for the product and demonstrate the relaxation of the enzyme after the exit of the product to resume the catalytic cycle.
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Affiliation(s)
- Navneet Bung
- TCS Innovation Labs-Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, India
| | - Meenakshi Pradhan
- TCS Innovation Labs-Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, India
| | - Harini Srinivasan
- TCS Innovation Labs-Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, India
| | - Gopalakrishnan Bulusu
- TCS Innovation Labs-Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, India
- * E-mail:
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Azim N, Deery E, Warren MJ, Wolfenden BAA, Erskine P, Cooper JB, Coker A, Wood SP, Akhtar M. Structural evidence for the partially oxidized dipyrromethene and dipyrromethanone forms of the cofactor of porphobilinogen deaminase: structures of the Bacillus megaterium enzyme at near-atomic resolution. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:744-51. [PMID: 24598743 PMCID: PMC3949521 DOI: 10.1107/s139900471303294x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/04/2013] [Indexed: 11/10/2022]
Abstract
The enzyme porphobilinogen deaminase (PBGD; hydroxymethylbilane synthase; EC 2.5.1.61) catalyses an early step of the tetrapyrrole-biosynthesis pathway in which four molecules of the monopyrrole porphobilinogen are condensed to form a linear tetrapyrrole. The enzyme possesses a dipyrromethane cofactor, which is covalently linked by a thioether bridge to an invariant cysteine residue (Cys241 in the Bacillus megaterium enzyme). The cofactor is extended during the reaction by the sequential addition of the four substrate molecules, which are released as a linear tetrapyrrole product. Expression in Escherichia coli of a His-tagged form of B. megaterium PBGD has permitted the X-ray analysis of the enzyme from this species at high resolution, showing that the cofactor becomes progressively oxidized to the dipyrromethene and dipyrromethanone forms. In previously solved PBGD structures, the oxidized cofactor is in the dipyromethenone form, in which both pyrrole rings are approximately coplanar. In contrast, the oxidized cofactor in the B. megaterium enzyme appears to be in the dipyrromethanone form, in which the C atom at the bridging α-position of the outer pyrrole ring is very clearly in a tetrahedral configuration. It is suggested that the pink colour of the freshly purified protein is owing to the presence of the dipyrromethene form of the cofactor which, in the structure reported here, adopts the same conformation as the fully reduced dipyrromethane form.
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Affiliation(s)
- N. Azim
- School of Biological Sciences, University of Punjab, New Campus, Lahore-54590, Pakistan
| | - E. Deery
- School of Biosciences, University of Kent, Stacey Building, Canterbury CT2 7NJ, England
| | - M. J. Warren
- School of Biosciences, University of Kent, Stacey Building, Canterbury CT2 7NJ, England
| | - B. A. A. Wolfenden
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - P. Erskine
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - J. B. Cooper
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - A. Coker
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - S. P. Wood
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - M. Akhtar
- School of Biological Sciences, University of Punjab, New Campus, Lahore-54590, Pakistan
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Azim N, Deery E, Warren MJ, Erskine P, Cooper JB, Wood SP, Akhtar M. Crystallization and preliminary X-ray characterization of the tetrapyrrole-biosynthetic enzyme porphobilinogen deaminase from Bacillus megaterium. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:906-8. [PMID: 23908040 PMCID: PMC3729171 DOI: 10.1107/s1744309113018526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 07/04/2013] [Indexed: 11/24/2022]
Abstract
The enzyme porphobilinogen deaminase (PBGD; hydroxymethylbilane synthase; EC 2.5.1.61) catalyses an early step of the tetrapyrrole-biosynthesis pathway in which four molecules of the monopyrrole porphobilinogen are condensed to form a linear tetrapyrrole. The enzyme possesses a dipyrromethane cofactor which is covalently linked by a thioether bridge to an invariant cysteine residue. Expression in Escherichia coli of a His-tagged form of Bacillus megaterium PBGD permitted the crystallization and preliminary X-ray analysis of the enzyme from this species at high resolution.
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Affiliation(s)
- N. Azim
- School of Biological Sciences, University of Punjab, New Campus, Lahore 54590, Pakistan
| | - E. Deery
- School of Biosciences, University of Kent, Stacey Building, Canterbury, Kent CT2 7NJ, England
| | - M. J. Warren
- School of Biosciences, University of Kent, Stacey Building, Canterbury, Kent CT2 7NJ, England
| | - P. Erskine
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - J. B. Cooper
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - S. P. Wood
- Laboratory of Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, UCL Division of Medicine (Royal Free Campus), Rowland Hill Street, London NW3 2PF, England
| | - M. Akhtar
- School of Biological Sciences, University of Punjab, New Campus, Lahore 54590, Pakistan
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