Effects of polymerization and nucleotide identity on the conformational dynamics of the bacterial actin homolog MreB.
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| Title: | Effects of polymerization and nucleotide identity on the conformational dynamics of the bacterial actin homolog MreB. |
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| Authors: | Colavin, Alexandre1,2, Hsin, Jen1, Casey Huang, Kerwyn1,2,3 kchuang@stanford.edu |
| Source: | Proceedings of the National Academy of Sciences of the United States of America. 3/4/2014, Vol. 111 Issue 9, p3585-3590. 6p. |
| Subjects: | Polymerization, Nucleotide sequence, Nucleotides, Eukaryotes, Hydrolysis |
| Abstract: | The assembly of protein filaments drives many cellular processes, from nucleoid segregation, growth, and division in single cells to muscle contraction in animals. In eukaryotes, shape and motility are regulated through cycles of polymerization and depolymerization of actin cytoskeletal networks. In bacteria, the actin homolog MreB forms filaments that coordinate the cell-wall synthesis machinery to regulate rod-shaped growth and contribute to cellular stiffness through unknown mechanisms. Like actin, MreB is an ATPase and requires ATP to polymerize, and polymerization promotes nucleotide hydrolysis. However, it is unclear whether other similarities exist between MreB and actin because the two proteins share low sequence identity and have distinct cellular roles. Here, we use all-atom molecular dynamics simulations to reveal surprising parallels between MreB and actin structural dynamics. We observe that MreB exhibits actin-like polymerization-dependent structural changes, wherein polymerization induces flattening of MreB subunits, which restructures the nucleotide-binding pocket to favor hydrolysis. MreB filaments exhibited nucleotide-dependent intersubunit bending, with hydrolyzed polymers favoring a straighter conformation.We use steered simulations to demonstrate a coupling between intersubunit bending and the degree of flattening of each subunit, suggesting cooperative bending along a filament. Taken together, our results provide molecular-scale insight into the diversity of structural states of MreB and the relationships among polymerization, hydrolysis, and filament properties, which may be applicable to other members of the broad actin family. [ABSTRACT FROM AUTHOR] |
| Copyright of Proceedings of the National Academy of Sciences of the United States of America is the property of National Academy of Sciences and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 94925924 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Effects of polymerization and nucleotide identity on the conformational dynamics of the bacterial actin homolog MreB. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Colavin%2C+Alexandre%22">Colavin, Alexandre</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Hsin%2C+Jen%22">Hsin, Jen</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Casey+Huang%2C+Kerwyn%22">Casey Huang, Kerwyn</searchLink><relatesTo>1,2,3</relatesTo><i> kchuang@stanford.edu</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Proceedings+of+the+National+Academy+of+Sciences+of+the+United+States+of+America%22">Proceedings of the National Academy of Sciences of the United States of America</searchLink>. 3/4/2014, Vol. 111 Issue 9, p3585-3590. 6p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Polymerization%22">Polymerization</searchLink><br /><searchLink fieldCode="DE" term="%22Nucleotide+sequence%22">Nucleotide sequence</searchLink><br /><searchLink fieldCode="DE" term="%22Nucleotides%22">Nucleotides</searchLink><br /><searchLink fieldCode="DE" term="%22Eukaryotes%22">Eukaryotes</searchLink><br /><searchLink fieldCode="DE" term="%22Hydrolysis%22">Hydrolysis</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: The assembly of protein filaments drives many cellular processes, from nucleoid segregation, growth, and division in single cells to muscle contraction in animals. In eukaryotes, shape and motility are regulated through cycles of polymerization and depolymerization of actin cytoskeletal networks. In bacteria, the actin homolog MreB forms filaments that coordinate the cell-wall synthesis machinery to regulate rod-shaped growth and contribute to cellular stiffness through unknown mechanisms. Like actin, MreB is an ATPase and requires ATP to polymerize, and polymerization promotes nucleotide hydrolysis. However, it is unclear whether other similarities exist between MreB and actin because the two proteins share low sequence identity and have distinct cellular roles. Here, we use all-atom molecular dynamics simulations to reveal surprising parallels between MreB and actin structural dynamics. We observe that MreB exhibits actin-like polymerization-dependent structural changes, wherein polymerization induces flattening of MreB subunits, which restructures the nucleotide-binding pocket to favor hydrolysis. MreB filaments exhibited nucleotide-dependent intersubunit bending, with hydrolyzed polymers favoring a straighter conformation.We use steered simulations to demonstrate a coupling between intersubunit bending and the degree of flattening of each subunit, suggesting cooperative bending along a filament. Taken together, our results provide molecular-scale insight into the diversity of structural states of MreB and the relationships among polymerization, hydrolysis, and filament properties, which may be applicable to other members of the broad actin family. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Proceedings of the National Academy of Sciences of the United States of America is the property of National Academy of Sciences and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1073/pnas.1317061111 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 6 StartPage: 3585 Subjects: – SubjectFull: Polymerization Type: general – SubjectFull: Nucleotide sequence Type: general – SubjectFull: Nucleotides Type: general – SubjectFull: Eukaryotes Type: general – SubjectFull: Hydrolysis Type: general Titles: – TitleFull: Effects of polymerization and nucleotide identity on the conformational dynamics of the bacterial actin homolog MreB. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Colavin, Alexandre – PersonEntity: Name: NameFull: Hsin, Jen – PersonEntity: Name: NameFull: Casey Huang, Kerwyn IsPartOfRelationships: – BibEntity: Dates: – D: 04 M: 03 Text: 3/4/2014 Type: published Y: 2014 Identifiers: – Type: issn-print Value: 00278424 Numbering: – Type: volume Value: 111 – Type: issue Value: 9 Titles: – TitleFull: Proceedings of the National Academy of Sciences of the United States of America Type: main |
| ResultId | 1 |
