1
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Ortega J, Lee GS, Gu L, Yang W, Li GM. Mispair-bound human MutS-MutL complex triggers DNA incisions and activates mismatch repair. Cell Res 2021; 31:542-553. [PMID: 33510387 PMCID: PMC8089094 DOI: 10.1038/s41422-021-00468-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/17/2020] [Indexed: 01/30/2023] Open
Abstract
DNA mismatch repair (MMR) relies on MutS and MutL ATPases for mismatch recognition and strand-specific nuclease recruitment to remove mispaired bases in daughter strands. However, whether the MutS-MutL complex coordinates MMR by ATP-dependent sliding on DNA or protein-protein interactions between the mismatch and strand discrimination signal is ambiguous. Using functional MMR assays and systems preventing proteins from sliding, we show that sliding of human MutSα is required not for MMR initiation, but for final mismatch removal. MutSα recruits MutLα to form a mismatch-bound complex, which initiates MMR by nicking the daughter strand 5' to the mismatch. Exonuclease 1 (Exo1) is then recruited to the nick and conducts 5' → 3' excision. ATP-dependent MutSα dissociation from the mismatch is necessary for Exo1 to remove the mispaired base when the excision reaches the mismatch. Therefore, our study has resolved a long-standing puzzle, and provided new insights into the mechanism of MMR initiation and mispair removal.
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Affiliation(s)
- Janice Ortega
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Grace Sanghee Lee
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY USA ,Present Address: Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Liya Gu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Wei Yang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD USA
| | - Guo-Min Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX USA ,Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY USA
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2
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Mardenborough YSN, Nitsenko K, Laffeber C, Duboc C, Sahin E, Quessada-Vial A, Winterwerp HHK, Sixma TK, Kanaar R, Friedhoff P, Strick TR, Lebbink JHG. The unstructured linker arms of MutL enable GATC site incision beyond roadblocks during initiation of DNA mismatch repair. Nucleic Acids Res 2020; 47:11667-11680. [PMID: 31598722 PMCID: PMC6902014 DOI: 10.1093/nar/gkz834] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 08/31/2019] [Accepted: 10/04/2019] [Indexed: 12/30/2022] Open
Abstract
DNA mismatch repair (MMR) maintains genome stability through repair of DNA replication errors. In Escherichia coli, initiation of MMR involves recognition of the mismatch by MutS, recruitment of MutL, activation of endonuclease MutH and DNA strand incision at a hemimethylated GATC site. Here, we studied the mechanism of communication that couples mismatch recognition to daughter strand incision. We investigated the effect of catalytically-deficient Cas9 as well as stalled RNA polymerase as roadblocks placed on DNA in between the mismatch and GATC site in ensemble and single molecule nanomanipulation incision assays. The MMR proteins were observed to incise GATC sites beyond a roadblock, albeit with reduced efficiency. This residual incision is completely abolished upon shortening the disordered linker regions of MutL. These results indicate that roadblock bypass can be fully attributed to the long, disordered linker regions in MutL and establish that communication during MMR initiation occurs along the DNA backbone.
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Affiliation(s)
| | - Katerina Nitsenko
- Institut Jacques Monod, CNRS, UMR7592, University Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France
| | - Charlie Laffeber
- Department of Molecular Genetics, Erasmus University Medical Center, Rotterdam, the Netherlands.,Oncode Institute, the Netherlands
| | - Camille Duboc
- Institut Jacques Monod, CNRS, UMR7592, University Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France
| | - Enes Sahin
- Department of Molecular Genetics, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Audrey Quessada-Vial
- Institut Jacques Monod, CNRS, UMR7592, University Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France
| | | | - Titia K Sixma
- Oncode Institute, the Netherlands.,Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Roland Kanaar
- Department of Molecular Genetics, Erasmus University Medical Center, Rotterdam, the Netherlands.,Oncode Institute, the Netherlands
| | - Peter Friedhoff
- Institute for Biochemistry, Justus-Liebig University, Giessen, Germany
| | - Terence R Strick
- Institut Jacques Monod, CNRS, UMR7592, University Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France.,Ecole Normale Supérieure, Institut de Biologie de l'Ecole Normale Superieure, CNRS, INSERM, PSL Research University, 75005 Paris, France.,Programme "Equipe Labellisée", Ligue Nationale contre le Cancer
| | - Joyce H G Lebbink
- Department of Molecular Genetics, Erasmus University Medical Center, Rotterdam, the Netherlands.,Department of Radiation Oncology, Erasmus University Medical Center, Rotterdam, the Netherlands
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3
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Wei W, Xiong L, Ye YN, Du MZ, Gao YZ, Zhang KY, Jin YT, Yang Z, Wong PC, Lau SKP, Kan B, Zhu J, Woo PCY, Guo FB. Mutation Landscape of Base Substitutions, Duplications, and Deletions in the Representative Current Cholera Pandemic Strain. Genome Biol Evol 2018; 10:2072-2085. [PMID: 30060177 PMCID: PMC6105331 DOI: 10.1093/gbe/evy151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2018] [Indexed: 01/03/2023] Open
Abstract
Pandemic cholera is a major concern for public health because of its high mortality and morbidity. Mutation accumulation (MA) experiments were performed on a representative strain of the current cholera pandemic. Although the base-pair substitution mutation rates in Vibrio cholerae (1.24 × 10-10 per site per generation for wild-type lines and 3.29 × 10-8 for mismatch repair deficient lines) are lower than that previously reported in other bacteria using MA analysis, we discovered specific high rates (8.31 × 10-8 site/generation for wild-type lines and 1.82 × 10-6 for mismatch repair deficient lines) of base duplication or deletion driven by large-scale copy number variations (CNVs). These duplication-deletions are located in two pathogenic islands, IMEX and the large integron island. Each element of these islands has discrepant rate in rapid integration and excision, which provides clues to the pandemicity evolution of V. cholerae. These results also suggest that large-scale structural variants such as CNVs can accumulate rapidly during short-term evolution. Mismatch repair deficient lines exhibit a significantly increased mutation rate in the larger chromosome (Chr1) at specific regions, and this pattern is not observed in wild-type lines. We propose that the high frequency of GATC sites in Chr1 improves the efficiency of MMR, resulting in similar rates of mutation in the wild-type condition. In addition, different mutation rates and spectra were observed in the MA lines under distinct growth conditions, including minimal media, rich media and antibiotic treatments.
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Affiliation(s)
- Wen Wei
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- School of Life Sciences, Chongqing University, China
| | - Lifeng Xiong
- Department of Microbiology, Research Centre of Infection and Immunology, State Key Laboratory of Emerging Infectious Diseases, and Carol Yu Centre for Infection, The University of Hong Kong, China
| | - Yuan-Nong Ye
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- Bioinformatics and Biomedical Bigdata Mining Laboratory, Key Laboratory of Biology and Medical Engineering, Guizhou Medical University, Guiyang, China
| | - Meng-Ze Du
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Yi-Zhou Gao
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Kai-Yue Zhang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Yan-Ting Jin
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Zujun Yang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
| | - Po-Chun Wong
- Department of Microbiology, Research Centre of Infection and Immunology, State Key Laboratory of Emerging Infectious Diseases, and Carol Yu Centre for Infection, The University of Hong Kong, China
| | - Susanna K P Lau
- Department of Microbiology, Research Centre of Infection and Immunology, State Key Laboratory of Emerging Infectious Diseases, and Carol Yu Centre for Infection, The University of Hong Kong, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, China
| | - Biao Kan
- National Institute for Communicable Disease Control and Prevention, State Key Laboratory of Infectious Disease Prevention and Control, Beijing, China
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania
| | - Patrick C Y Woo
- Department of Microbiology, Research Centre of Infection and Immunology, State Key Laboratory of Emerging Infectious Diseases, and Carol Yu Centre for Infection, The University of Hong Kong, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, China
| | - Feng-Biao Guo
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu, China
- Key Laboratory for NeuroInformation of the Ministry of Education, University of Electronic Science and Technology of China, Chengdu, China
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4
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WITHDRAWN: In memory of John Bruce Hays (1937–2014). DNA Repair (Amst) 2017. [DOI: 10.1016/j.dnarep.2014.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Ishida H, Matsumoto A. Mechanism for verification of mismatched and homoduplex DNAs by nucleotides-bound MutS analyzed by molecular dynamics simulations. Proteins 2016; 84:1287-303. [PMID: 27238299 DOI: 10.1002/prot.25077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/13/2016] [Accepted: 05/24/2016] [Indexed: 11/10/2022]
Abstract
In order to understand how MutS recognizes mismatched DNA and induces the reaction of DNA repair using ATP, the dynamics of the complexes of MutS (bound to the ADP and ATP nucleotides, or not) and DNA (with mismatched and matched base-pairs) were investigated using molecular dynamics simulations. As for DNA, the structure of the base-pairs of the homoduplex DNA which interacted with the DNA recognition site of MutS was intermittently disturbed, indicating that the homoduplex DNA was unstable. As for MutS, the disordered loops in the ATPase domains, which are considered to be necessary for the induction of DNA repair, were close to (away from) the nucleotide-binding sites in the ATPase domains when the nucleotides were (not) bound to MutS. This indicates that the ATPase domains changed their structural stability upon ATP binding using the disordered loop. Conformational analysis by principal component analysis showed that the nucleotide binding changed modes which have structurally solid ATPase domains and the large bending motion of the DNA from higher to lower frequencies. In the MutS-mismatched DNA complex bound to two nucleotides, the bending motion of the DNA at low frequency modes may play a role in triggering the formation of the sliding clamp for the following DNA-repair reaction step. Moreover, MM-PBSA/GBSA showed that the MutS-homoduplex DNA complex bound to two nucleotides was unstable because of the unfavorable interactions between MutS and DNA. This would trigger the ATP hydrolysis or separation of MutS and DNA to continue searching for mismatch base-pairs. Proteins 2016; 84:1287-1303. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Hisashi Ishida
- Quantum Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai Kizugawa-Shi, Kyoto, 619-0215, Japan
| | - Atsushi Matsumoto
- Quantum Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai Kizugawa-Shi, Kyoto, 619-0215, Japan
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6
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Negureanu L, Salsbury FR. Insights into protein - DNA interactions, stability and allosteric communications: a computational study of mutSα-DNA recognition complexes. J Biomol Struct Dyn 2016; 29:757-76. [PMID: 22208277 DOI: 10.1080/07391102.2012.10507412] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
DNA mismatch repair proteins (MMR) maintain genetic stability by recognizing and repairing mismatched bases and insertion/deletion loops mistakenly incorporated during DNA replication, and initiate cellular response to certain types of DNA damage. Loss of MMR in mammalian cells has been linked to resistance to certain DNA damaging chemotherapeutic agents, as well as to increase risk of cancer. Mismatch repair pathway is considered to involve the concerted action of at least 20 proteins. The most abundant MMR mismatch-binding factor in eukaryotes, MutSα, recognizes and initiates the repair of base-base mismatches and small insertion/deletion. We performed molecular dynamics simulations on mismatched and damaged MutSα-DNA complexes. A comprehensive DNA binding site analysis of relevant conformations shows that MutSα proteins recognize the mismatched and platinum cross-linked DNA substrates in significantly different modes. Distinctive conformational changes associated with MutSα binding to mismatched and damaged DNA have been identified and they provide insight into the involvement of MMR proteins in DNA-repair and DNA-damage pathways. Stability and allosteric interactions at the heterodimer interface associated with the mismatch and damage recognition step allow for prediction of key residues in MMR cancer-causing mutations. A rigorous hydrogen bonding analysis for ADP molecules at the ATPase binding sites is also presented. Due to extended number of known MMR cancer causing mutations among the residues proved to make specific contacts with ADP molecules, recommendations for further studies on similar mutagenic effects were made.
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7
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Chromosomal directionality of DNA mismatch repair in Escherichia coli. Proc Natl Acad Sci U S A 2015; 112:9388-93. [PMID: 26170312 DOI: 10.1073/pnas.1505370112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Defects in DNA mismatch repair (MMR) result in elevated mutagenesis and in cancer predisposition. This disease burden arises because MMR is required to correct errors made in the copying of DNA. MMR is bidirectional at the level of DNA strand polarity as it operates equally well in the 5' to 3' and the 3' to 5' directions. However, the directionality of MMR with respect to the chromosome, which comprises parental DNA strands of opposite polarity, has been unknown. Here, we show that MMR in Escherichia coli is unidirectional with respect to the chromosome. Our data demonstrate that, following the recognition of a 3-bp insertion-deletion loop mismatch, the MMR machinery searches for the first hemimethylated GATC site located on its origin-distal side, toward the replication fork, and that resection then proceeds back toward the mismatch and away from the replication fork. This study provides support for a tight coupling between MMR and DNA replication.
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8
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de Wind N, Buermeyer AB, Hanawalt PC. In memory of John Bruce Hays (1937-2014). DNA Repair (Amst) 2014; 16:vi-vii. [PMID: 24674631 DOI: 10.1016/s1568-7864(14)00071-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Indexed: 10/25/2022]
Affiliation(s)
- Niels de Wind
- Department of Toxicogenetics, Leiden University Medical Center, The Netherlands.
| | - Andrew B Buermeyer
- Department of Environmental and Molecular Toxicology, Oregon State University, United States
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9
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Abstract
The mismatch repair (MMR) system detects non-Watson-Crick base pairs and strand misalignments arising during DNA replication and mediates their removal by catalyzing excision of the mispair-containing tract of nascent DNA and its error-free resynthesis. In this way, MMR improves the fidelity of replication by several orders of magnitude. It also addresses mispairs and strand misalignments arising during recombination and prevents synapses between nonidentical DNA sequences. Unsurprisingly, MMR malfunction brings about genomic instability that leads to cancer in mammals. But MMR proteins have recently been implicated also in other processes of DNA metabolism, such as DNA damage signaling, antibody diversification, and repair of interstrand cross-links and oxidative DNA damage, in which their functions remain to be elucidated. This article reviews the progress in our understanding of the mechanism of replication error repair made during the past decade.
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Affiliation(s)
- Josef Jiricny
- Institute of Molecular Cancer Research, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland.
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10
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Luzzietti N, Knappe S, Richter I, Seidel R. Nicking enzyme-based internal labeling of DNA at multiple loci. Nat Protoc 2012; 7:643-53. [PMID: 22402634 DOI: 10.1038/nprot.2012.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The labeling of biomolecules has become standard practice in molecular biosciences. Modifications are used for detection, sorting and isolation of small molecules, complexes and entire cells. We have recently reported a method for introducing internal chemical and structural modifications into kbp-sized DNA target substrates that are frequently used in single-molecule experiments. It makes use of nicking enzymes that create single-stranded DNA gaps, which can be subsequently filled with labeled oligonucleotides. Here we provide a detailed protocol and further expand this method. We show that modifications can be introduced at distant loci within one molecule in a simple one-pot reaction. In addition, we achieve labeling on both strands at a specific locus, as demonstrated by Förster resonance energy transfer (FRET) experiments. The protocol requires an initial cloning of the target substrate (3-5 d), whereas the labeling itself takes 4-6 h. More elaborate purification and verification of label incorporation requires 2 h for each method.
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Affiliation(s)
- Nicholas Luzzietti
- Biotechnology Center, Dresden University of Technology, Dresden, Germany
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11
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The functions of MutL in mismatch repair: the power of multitasking. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 110:41-70. [PMID: 22749142 DOI: 10.1016/b978-0-12-387665-2.00003-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
DNA mismatch repair enhances genomic stability by correcting errors that have escaped polymerase proofreading. One of the critical steps in DNA mismatch repair is discriminating the new from the parental DNA strand as only the former needs repair. In Escherichia coli, the latent endonuclease MutH carries out this function. However, most prokaryotes and all eukaryotes lack a mutH gene. MutL is a key component of this system that mediates protein-protein interactions during mismatch recognition, strand discrimination, and strand removal. Hence, it had long been thought that the primary function of MutL was coordinating sequential mismatch repair steps. However, recent studies have revealed that most MutL homologs from organisms lacking MutH encode a conserved metal-binding motif associated with a weak endonuclease activity. As MutL homologs bearing this activity are found only in organisms relying on MutH-independent DNA mismatch repair, this finding unveils yet another crucial function of the MutL protein at the strand discrimination step. In this chapter, we review recent functional and structural work aimed at characterizing the multiple functions of MutL and discuss how the endonuclease activity of MutL is regulated by other repair factors.
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12
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Atomic force microscopy captures MutS tetramers initiating DNA mismatch repair. EMBO J 2011; 30:2881-93. [PMID: 21666597 DOI: 10.1038/emboj.2011.180] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 05/10/2011] [Indexed: 11/09/2022] Open
Abstract
In spite of extensive research, the mechanism by which MutS initiates DNA mismatch repair (MMR) remains controversial. We use atomic force microscopy (AFM) to capture how MutS orchestrates the first step of E. coli MMR. AFM images captured two types of MutS/DNA complexes: single-site binding and loop binding. In most of the DNA loops imaged, two closely associated MutS dimers formed a tetrameric complex in which one of the MutS dimers was located at or near the mismatch. Surprisingly, in the presence of ATP, one MutS dimer remained at or near the mismatch site and the other, while maintaining contact with the first dimer, relocated on the DNA by reeling in DNA, thereby producing expanding DNA loops. Our results indicate that MutS tetramers composed of two non-equivalent MutS dimers drive E. coli MMR, and these new observations now reconcile the apparent contradictions of previous 'sliding' and 'bending/looping' models of interaction between mismatch and strand signal.
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13
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Isolated short CTG/CAG DNA slip-outs are repaired efficiently by hMutSbeta, but clustered slip-outs are poorly repaired. Proc Natl Acad Sci U S A 2010; 107:12593-8. [PMID: 20571119 DOI: 10.1073/pnas.0909087107] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Expansions of CTG/CAG trinucleotide repeats, thought to involve slipped DNAs at the repeats, cause numerous diseases including myotonic dystrophy and Huntington's disease. By unknown mechanisms, further repeat expansions in transgenic mice carrying expanded CTG/CAG tracts require the mismatch repair (MMR) proteins MSH2 and MSH3, forming the MutSbeta complex. Using an in vitro repair assay, we investigated the effect of slip-out size, with lengths of 1, 3, or 20 excess CTG repeats, as well as the effect of the number of slip-outs per molecule, on the requirement for human MMR. Long slip-outs escaped repair, whereas short slip-outs were repaired efficiently, much greater than a G-T mismatch, but required hMutSbeta. Higher or lower levels of hMutSbeta or its complete absence were detrimental to proper repair of short slip-outs. Surprisingly, clusters of as many as 62 short slip-outs (one to three repeat units each) along a single DNA molecule with (CTG)50*(CAG)50 repeats were refractory to repair, and repair efficiency was reduced further without MMR. Consistent with the MutSbeta requirement for instability, hMutSbeta is required to process isolated short slip-outs; however, multiple adjacent short slip-outs block each other's repair, possibly acting as roadblocks to progression of repair and allowing error-prone repair. Results suggest that expansions can arise by escaped repair of long slip-outs, tandem short slip-outs, or isolated short slip-outs; the latter two types are sensitive to hMutSbeta. Poor repair of clustered DNA lesions has previously been associated only with ionizing radiation damage. Our results extend this interference in repair to neurodegenerative disease-causing mutations in which clustered slip-outs escape proper repair and lead to expansions.
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Abstract
Many biological processes rely on the interaction of proteins with multiple DNA sites separated by thousands of base pairs. These long-range communication events can be driven by both the thermal motions of proteins and DNA, and directional protein motions that are rectified by ATP hydrolysis. The present review describes conflicting experiments that have sought to explain how the ATP-dependent Type III restriction-modification enzymes can cut DNA with two sites in an inverted repeat, but not DNA with two sites in direct repeat. We suggest that an ATPase activity may not automatically indicate a DNA translocase, but can alternatively indicate a molecular switch that triggers communication by thermally driven DNA sliding. The generality of this mechanism to other ATP-dependent communication processes such as mismatch repair is also discussed.
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15
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Hsieh P, Yamane K. DNA mismatch repair: molecular mechanism, cancer, and ageing. Mech Ageing Dev 2008; 129:391-407. [PMID: 18406444 PMCID: PMC2574955 DOI: 10.1016/j.mad.2008.02.012] [Citation(s) in RCA: 291] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Revised: 02/22/2008] [Accepted: 02/28/2008] [Indexed: 02/09/2023]
Abstract
DNA mismatch repair (MMR) proteins are ubiquitous players in a diverse array of important cellular functions. In its role in post-replication repair, MMR safeguards the genome correcting base mispairs arising as a result of replication errors. Loss of MMR results in greatly increased rates of spontaneous mutation in organisms ranging from bacteria to humans. Mutations in MMR genes cause hereditary nonpolyposis colorectal cancer, and loss of MMR is associated with a significant fraction of sporadic cancers. Given its prominence in mutation avoidance and its ability to target a range of DNA lesions, MMR has been under investigation in studies of ageing mechanisms. This review summarizes what is known about the molecular details of the MMR pathway and the role of MMR proteins in cancer susceptibility and ageing.
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Affiliation(s)
- Peggy Hsieh
- Genetics & Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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16
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Abstract
DNA mismatch repair (MMR) is a highly conserved biological pathway that plays a key role in maintaining genomic stability. The specificity of MMR is primarily for base-base mismatches and insertion/deletion mispairs generated during DNA replication and recombination. MMR also suppresses homeologous recombination and was recently shown to play a role in DNA damage signaling in eukaryotic cells. Escherichia coli MutS and MutL and their eukaryotic homologs, MutSalpha and MutLalpha, respectively, are key players in MMR-associated genome maintenance. Many other protein components that participate in various DNA metabolic pathways, such as PCNA and RPA, are also essential for MMR. Defects in MMR are associated with genome-wide instability, predisposition to certain types of cancer including hereditary non-polyposis colorectal cancer, resistance to certain chemotherapeutic agents, and abnormalities in meiosis and sterility in mammalian systems.
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17
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Abstract
A fundamental question in DNA repair is how a lesion is detected when embedded in millions to billions of normal base pairs. Extensive structural and functional studies reveal atomic details of DNA repair protein and nucleic acid interactions. This review summarizes seemingly diverse structural motifs used in lesion recognition and suggests a general mechanism to recognize DNA lesion by the poor base stacking. After initial recognition of this shared structural feature of lesions, different DNA repair pathways use unique verification mechanisms to ensure correct lesion identification and removal.
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18
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Wang H, Hays JB. Human DNA mismatch repair: coupling of mismatch recognition to strand-specific excision. Nucleic Acids Res 2007; 35:6727-39. [PMID: 17921148 PMCID: PMC2175295 DOI: 10.1093/nar/gkm734] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Revised: 08/23/2007] [Accepted: 09/04/2007] [Indexed: 11/16/2022] Open
Abstract
Eukaryotic mismatch-repair (MMR) proteins MutSalpha and MutLalpha couple recognition of base mismatches to strand-specific excision, initiated in vivo at growing 3' ends and 5' Okazaki-fragment ends or, in human nuclear extracts, at nicks in exogenous circular substrates. We addressed five biochemical questions relevant to coupling models. Excision remained fully efficient at DNA:MutSalpha ratios of nearly 1 to 1 at various mismatch-nick distances, suggesting a requirement for only one MutSalpha molecule per substrate. As the mismatch-nick DNA contour distance D in exogenous substrates increased from 0.26 to 0.98 kbp, initiation of excision in extracts decreased as D(-0.43) rather than the D(-1) to D(-2) predicted by some translocation or diffusion models. Virtually all excision was along the shorter (3'-5') nick-mismatch, even when the other (5'-3') path was less than twice as long. These observations argue against stochastically directed translocating/diffusing recognition complexes. The failure of mismatched DNA in trans to provoke excision of separate nicked homoduplexes argues against one-stage (concerted) triggering of excision initiation by recognition complexes acting through space. However, proteins associated with gapped DNA did appear to compete in trans with those in cis to mismatch-associated proteins. Thus, as in Escherichia coli, eukaryotic MMR may involve distinct initial-activation and excision-path-commitment stages.
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Affiliation(s)
| | - John B. Hays
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis OR 97331-7301, USA
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19
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Kolodner RD, Mendillo ML, Putnam CD. Coupling distant sites in DNA during DNA mismatch repair. Proc Natl Acad Sci U S A 2007; 104:12953-4. [PMID: 17664420 PMCID: PMC1941800 DOI: 10.1073/pnas.0705698104] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Richard D Kolodner
- Ludwig Institute for Cancer Research, Department of Medicine, University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0669, USA.
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Pluciennik A, Modrich P. Protein roadblocks and helix discontinuities are barriers to the initiation of mismatch repair. Proc Natl Acad Sci U S A 2007; 104:12709-13. [PMID: 17620611 PMCID: PMC1913546 DOI: 10.1073/pnas.0705129104] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The hemimethylated d(GATC) sequence that directs Escherichia coli mismatch repair can reside on either side of a mismatch at a separation distance of 1,000 bp or more. Initiation of repair involves the mismatch-, MutS-, and MutL-dependent activation of MutH endonuclease, which incises the unmethylated strand at the d(GATC) sequence, with the ensuing strand break serving as the loading site for the appropriate 3'-to-5' or 5'-to-3' excision system. However, the mechanism responsible for the coordinated recognition of the mismatch and a hemimodified d(GATC) site is uncertain. We show that a protein roadblock (EcoRI(E111Q), a hydrolytically defective form of EcoRI endonuclease) placed on the helix between the two DNA sites inhibits MutH activation by 70-80% and that events that escape inhibition are attributable, at least in part, to diffusion of EcoRI(E111Q) away from its recognition site. We also demonstrate that a double-strand break located within the shorter path linking the mismatch and a d(GATC) site in a circular heteroduplex abolishes MutH activation, whereas a double-strand break within the longer path is without effect. These findings support the idea that initiation of mismatch repair involves signaling along the helix contour.
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Affiliation(s)
| | - Paul Modrich
- Department of Biochemistry and
- Howard Hughes Medical Institute, Box 3711, Duke University Medical Center, Durham, NC 27710
- To whom correspondence should be addressed. E-mail:
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21
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Plotz G, Zeuzem S, Raedle J. DNA mismatch repair and Lynch syndrome. J Mol Histol 2006; 37:271-83. [PMID: 16821093 DOI: 10.1007/s10735-006-9038-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Accepted: 06/06/2006] [Indexed: 01/31/2023]
Abstract
The evolutionary conserved mismatch repair proteins correct a wide range of DNA replication errors. Their importance as guardians of genetic integrity is reflected by the tremendous decrease of replication fidelity (two to three orders of magnitude) conferred by their loss. Germline mutations in mismatch repair genes, predominantly MSH2 and MLH1, have been found to underlie the Lynch syndrome (also called hereditary non-polyposis colorectal cancer, HNPCC), a hereditary predisposition for cancer. Lynch syndrome affects predominantly the colon and accounts for 2-5% of all colon cancer cases. During more than 30 years of biochemical, crystallographic and clinical research, deep insight has been achieved in the function of mismatch repair and the diseases that are associated with its loss. We review the biochemistry of mismatch repair and also introduce the clinical, diagnostic and genetic aspects of Lynch syndrome.
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Affiliation(s)
- Guido Plotz
- Klinik für Innere Medizin II, Universitätsklinikum des Saarlandes, Kirrberger Strasse, Gebäude 41, D-66421 Homburg, Germany.
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Abstract
By removing biosynthetic errors from newly synthesized DNA, mismatch repair (MMR) improves the fidelity of DNA replication by several orders of magnitude. Loss of MMR brings about a mutator phenotype, which causes a predisposition to cancer. But MMR status also affects meiotic and mitotic recombination, DNA-damage signalling, apoptosis and cell-type-specific processes such as class-switch recombination, somatic hypermutation and triplet-repeat expansion. This article reviews our current understanding of this multifaceted DNA-repair system in human cells.
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Affiliation(s)
- Josef Jiricny
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
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23
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Wang H, Hoffman PD, Lawrence C, Hays JB. Testing excision models for responses of mismatch-repair systems to UV photoproducts in DNA. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2006; 47:296-306. [PMID: 16493608 DOI: 10.1002/em.20206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Mismatch-repair (MMR) systems correct DNA replication errors and respond to a variety of DNA lesions. Previous observations that MMR antagonizes UV mutagenesis, and that the mismatch-recognition protein heterodimer MSH2*MSH6 (MutSalpha) selectively binds DNA containing "mismatched" photoproducts (T[CPD]T/AG, T[6-4]T/AG) but not "matched" photoproducts (T[CPD]T/AA, T[6-4]T/AA), suggested that mismatched photoproducts would provoke MMR excision similar to mismatched bases. Excision of incorrect nucleotides inserted opposite template photoproducts might then prevent UV-induced mutation. We tested T[CPD]T/AG DNA, in a sequence context in which it is bound substantially by hMutSalpha and in three other contexts, for stimulation of 3' MMR excision in mammalian nuclear extracts. T[CPD]T/AG was inactive in HeLa extracts, or in extracts deficient in the photoproduct-binding proteins DDB or XPC* hHR23B, arguing against interference from the nucleotide excision repair pathway. Prior incubation with hMutSalpha and MLH2.PMS2 (hMutLalpha) did not increase excision relative to homoduplex controls. T[6-4]T/AG also failed to provoke excision. T/G, C/A, and T/T substrates, even though bound by hMutSalpha no better than T[CPD]T/AG substrates, efficiently provoked excision. Even a substrate containing three T[CPD]T/AG photoproducts (in different contexts) did not significantly provoke excision. Thus, MMR may suppress UV mutagenesis by non-excisive mechanisms.
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Affiliation(s)
- Huxian Wang
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, USA
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Affiliation(s)
- Ravi R Iyer
- Department of Biochemistry and Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA
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López de Saro FJ, Marinus MG, Modrich P, O'Donnell M. The beta sliding clamp binds to multiple sites within MutL and MutS. J Biol Chem 2006; 281:14340-9. [PMID: 16546997 DOI: 10.1074/jbc.m601264200] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The MutL and MutS proteins are the central components of the DNA repair machinery that corrects mismatches generated by DNA polymerases during synthesis. We find that MutL interacts directly with the beta sliding clamp, a ring-shaped dimeric protein that confers processivity to DNA polymerases by tethering them to their substrates. Interestingly, the interaction of MutL with beta only occurs in the presence of single-stranded DNA. We find that the interaction occurs via a loop in MutL near the ATP-binding site. The binding site of MutL on beta locates to the hydrophobic pocket between domains two and three of the clamp. Site-specific replacement of two residues in MutL diminished interaction with beta without disrupting MutL function with helicase II. In vivo studies reveal that this mutant MutL is no longer functional in mismatch repair. In addition, the human MLH1 has a close match to the proliferating cell nuclear antigen clamp binding motif in the region that corresponds to the beta interaction site in Escherichia coli MutL, and a peptide corresponding to this site binds proliferating cell nuclear antigen. The current report also examines in detail the interaction of beta with MutS. We find that two distinct regions of MutS interact with beta. One is located near the C terminus and the other is close to the N terminus, within the mismatch binding domain. Complementation studies using genes encoding different MutS mutants reveal that the N-terminal beta interaction motif on MutS is essential for activity in vivo, but the C-terminal interaction site for beta is not. In light of these results, we propose roles for the beta clamp in orchestrating the sequence of events that lead to mismatch repair in the cell.
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26
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Joseph N, Duppatla V, Rao DN. Prokaryotic DNA Mismatch Repair. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2006; 81:1-49. [PMID: 16891168 DOI: 10.1016/s0079-6603(06)81001-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Nimesh Joseph
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
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27
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Abstract
Evolutionarily-conserved mismatch-repair (MMR) systems correct all or almost all base-mismatch errors from DNA replication via excision-resynthesis pathways, and respond to many different DNA lesions. Consideration of DNA polymerase error rates and possible consequences of excess gratuitous excision of perfectly paired (homoduplex) DNA in vivo suggests that MMR needs to discriminate against homoduplex DNA by three to six orders of magnitude. However, numerous binding studies using MMR base-mispair-recognition proteins, bacterial MutS or eukaryotic MSH2.MSH6 (MutSalpha), have typically shown discrimination factors between mismatched and homoduplex DNA to be 5-30, depending on the binding conditions, the particular mismatches, and the DNA-sequence contexts. Thus, downstream post-binding steps must increase MMR discrimination without interfering with the versatility needed to recognize a large variety of base-mismatches and lesions. We use a complex but highly MMR-active model system, human nuclear extracts mixed with plasmid substrates containing specific mismatches and defined nicks 0.15 kbp away, to measure the earliest quantifiable committed step in mismatch correction, initiation of mismatch-provoked 3'-5' excision at the nicks. We compared these results to binding of purified MutSalpha to synthetic oligoduplexes containing the same mismatches in the same sequence contexts, under conditions very similar to those prevailing in the nuclear extracts. Discrimination against homoduplex DNA, only two-to five-fold in the binding studies, increased to 60- to 230-fold or more for excision initiation, depending on the particular mismatches. Remarkably, the mismatch-preference order for excision initiation was substantially altered from the order for hMutSalpha binding. This suggests that post-binding steps not only strongly discriminate against homoduplex DNA, but do so by mechanisms not tightly constrained by initial binding preferences. Pairs of homoduplexes (40, 50, and 70 bp) prepared from synthetic oligomers or cut out of plasmids showed virtually identical hMutSalpha binding affinities, suggesting that high hMutSalpha binding to homoduplex DNA is not the result of misincorporations or lesions introduced during chemical synthesis. Intrinsic affinities of MutS homologs for perfectly paired DNA may help these proteins efficiently position themselves to carry out subsequent mismatch-specific steps in MMR pathways.
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Affiliation(s)
- John B Hays
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, 97331-7301, USA.
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28
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Antony E, Khubchandani S, Chen S, Hingorani MM. Contribution of Msh2 and Msh6 subunits to the asymmetric ATPase and DNA mismatch binding activities of Saccharomyces cerevisiae Msh2-Msh6 mismatch repair protein. DNA Repair (Amst) 2005; 5:153-62. [PMID: 16214425 PMCID: PMC4674293 DOI: 10.1016/j.dnarep.2005.08.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 08/22/2005] [Accepted: 08/25/2005] [Indexed: 12/13/2022]
Abstract
Previous analyses of both Thermus aquaticus MutS homodimer and Saccharomyces cerevisiae Msh2-Msh6 heterodimer have revealed that the subunits in these protein complexes bind and hydrolyze ATP asymmetrically, emulating their asymmetric DNA binding properties. In the MutS homodimer, one subunit (S1) binds ATP with high affinity and hydrolyzes it rapidly, while the other subunit (S2) binds ATP with lower affinity and hydrolyzes it at an apparently slower rate. Interaction of MutS with mismatched DNA results in suppression of ATP hydrolysis at S1-but which of these subunits, S1 or S2, makes specific contact with the mismatch (e.g., base stacking by a conserved phenylalanine residue) remains unknown. In order to answer this question and to clarify the links between the DNA binding and ATPase activities of each subunit in the dimer, we made mutations in the ATPase sites of Msh2 and Msh6 and assessed their impact on the activity of the Msh2-Msh6 heterodimer (in Msh2-Msh6, only Msh6 makes base specific contact with the mismatch). The key findings are: (a) Msh6 hydrolyzes ATP rapidly, and thus resembles the S1 subunit of the MutS homodimer, (b) Msh2 hydrolyzes ATP at a slower rate, and thus resembles the S2 subunit of MutS, (c) though itself an apparently weak ATPase, Msh2 has a strong influence on the ATPase activity of Msh6, (d) Msh6 binding to mismatched DNA results in suppression of rapid ATP hydrolysis, revealing a "cis" linkage between its mismatch recognition and ATPase activities, (e) the resultant Msh2-Msh6 complex, with both subunits in the ATP-bound state, exhibits altered interactions with the mismatch.
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Affiliation(s)
| | | | | | - Manju M. Hingorani
- Corresponding author. Tel.: +1 860 685 2284; fax: +1 860 685 2141. (M.M. Hingorani)
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29
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Abstract
DNA mismatch repair (MMR) is an evolutionarily conserved process that corrects mismatches generated during DNA replication and escape proofreading. MMR proteins also participate in many other DNA transactions, such that inactivation of MMR can have wide-ranging biological consequences, which can be either beneficial or detrimental. We begin this review by briefly considering the multiple functions of MMR proteins and the consequences of impaired function. We then focus on the biochemical mechanism of MMR replication errors. Emphasis is on structure-function studies of MMR proteins, on how mismatches are recognized, on the process by which the newly replicated strand is identified, and on excision of the replication error.
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Affiliation(s)
- Thomas A Kunkel
- Laboratory of Molecular Genetics and Laboratory of Structural Biology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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30
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Marra G, Jiricny J. DNA mismatch repair and colon cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2005; 570:85-123. [PMID: 18727499 DOI: 10.1007/1-4020-3764-3_4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Giancarlo Marra
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
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31
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Antony E, Hingorani MM. Asymmetric ATP binding and hydrolysis activity of the Thermus aquaticus MutS dimer is key to modulation of its interactions with mismatched DNA. Biochemistry 2004; 43:13115-28. [PMID: 15476405 PMCID: PMC2839884 DOI: 10.1021/bi049010t] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Prokaryotic MutS and eukaryotic Msh proteins recognize base pair mismatches and insertions or deletions in DNA and initiate mismatch repair. These proteins function as dimers (and perhaps higher order oligomers) and possess an ATPase activity that is essential for DNA repair. Previous studies of Escherichia coli MutS and eukaryotic Msh2-Msh6 proteins have revealed asymmetry within the dimer with respect to both DNA binding and ATPase activities. We have found the Thermus aquaticus MutS protein amenable to detailed investigation of the nature and role of this asymmetry. Here, we show that (a) in a MutS dimer one subunit (S1) binds nucleotide with high affinity and the other (S2) with 10-fold weaker affinity, (b) S1 hydrolyzes ATP rapidly while S2 hydrolyzes ATP at a 30-50-fold slower rate, (c) mismatched DNA binding to MutS inhibits ATP hydrolysis at S1 but slow hydrolysis continues at S2, and (d) interaction between mismatched DNA and MutS is weakened when both subunits are occupied by ATP but remains stable when S1 is occupied by ATP and S2 by ADP. These results reveal key MutS species in the ATPase pathway; S1(ADP)-S2(ATP) is formed preferentially in the absence of DNA or in the presence of fully matched DNA, while S1(ATP)-S2(ATP) and S1(ATP)-S2(ADP) are formed preferentially in the presence of mismatched DNA. These MutS species exhibit differences in interaction with mismatched DNA that are likely important for the mechanism of MutS action in DNA repair.
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32
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Guarné A, Ramon-Maiques S, Wolff EM, Ghirlando R, Hu X, Miller JH, Yang W. Structure of the MutL C-terminal domain: a model of intact MutL and its roles in mismatch repair. EMBO J 2004; 23:4134-45. [PMID: 15470502 PMCID: PMC524388 DOI: 10.1038/sj.emboj.7600412] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Accepted: 08/20/2004] [Indexed: 12/19/2022] Open
Abstract
MutL assists the mismatch recognition protein MutS to initiate and coordinate mismatch repair in species ranging from bacteria to humans. The MutL N-terminal ATPase domain is highly conserved, but the C-terminal region shares little sequence similarity among MutL homologs. We report here the crystal structure of the Escherichia coli MutL C-terminal dimerization domain and the likelihood of its conservation among MutL homologs. A 100-residue proline-rich linker between the ATPase and dimerization domains, which generates a large central cavity in MutL dimers, tolerates sequence substitutions and deletions of one-third of its length with no functional consequences in vivo or in vitro. Along the surface of the central cavity, residues essential for DNA binding are located in both the N- and C-terminal domains. Each domain of MutL interacts with UvrD helicase and is required for activating the helicase activity. The DNA-binding capacity of MutL is correlated with the level of UvrD activation. A model of how MutL utilizes its ATPase and DNA-binding activities to mediate mismatch-dependent activation of MutH endonuclease and UvrD helicase is proposed.
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Affiliation(s)
- Alba Guarné
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Santiago Ramon-Maiques
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Erika M Wolff
- Department of Microbiology, Immunology, and Molecular Genetics, The Molecular Biology Institute, University of California, Los Angeles, CA, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Xiaojian Hu
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jeffrey H Miller
- Department of Microbiology, Immunology, and Molecular Genetics, The Molecular Biology Institute, University of California, Los Angeles, CA, USA
| | - Wei Yang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Building 5, Rm B1-03, Bethesda, MD 20892, USA. Tel.: +1 301 402 4645; Fax: +1 301 496 0201; E-mail:
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