Conformational changes of FtsZ reported by tryptophan mutants.

dc.contributor.author

Chen, Yaodong

dc.contributor.author

Erickson, Harold P

dc.date.accessioned

2018-04-01T14:58:57Z

dc.date.available

2018-04-01T14:58:57Z

dc.date.issued

2011-05-03

dc.date.updated

2018-04-01T14:58:57Z

dc.description.abstract

E. coli FtsZ has no native tryptophan. We showed previously that the mutant FtsZ L68W gave a 2.5-fold increase in trp fluorescence when assembly was induced by GTP. L68 is probably buried in the protofilament interface upon assembly, causing the fluorescence increase. In the present study we introduced trp residues at several other locations and examined them for assembly-induced fluorescence changes. L189W, located on helix H7 and buried between the N- and C-terminal subdomains, showed a large fluorescence increase, comparable to L68W. This may reflect a shift or rotation of the two subdomains relative to each other. L160W showed a smaller increase in fluorescence, and Y222W a decrease in fluorescence, upon assembly. These two are located on the surface of the N and C subdomains, near the domain boundary. The changes in fluorescence may reflect movements of the domains or of nearby side chains. We prepared a double mutant Y222W/S151C and coupled ATTO-655 to the cys. The Cα of trp in the C-terminal subdomain was 10 Å away from that of the cys in the N-terminal subdomain, permitting the ATTO to make van der Waals contact with the trp. The ATTO fluorescence showed strong tryptophan-induced quenching. The quenching was reduced following assembly, consistent with a movement apart of the two subdomains. Movements of one to several angstroms are probably sufficient to account for the changes in trp fluorescence and trp-induced quenching of ATTO. Assembly in GDP plus DEAE dextran produces tubular polymers that are related to the highly curved, mini-ring conformation. No change in trp fluorescence was observed upon assembly of these tubes, suggesting that the mini-ring conformation is the same as that of a relaxed, monomeric FtsZ.

dc.identifier.issn

0006-2960

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1520-4995

dc.identifier.uri

https://hdl.handle.net/10161/16460

dc.language

eng

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American Chemical Society (ACS)

dc.relation.ispartof

Biochemistry

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10.1021/bi200106d

dc.subject

Acrylamide

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Tryptophan

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Bacterial Proteins

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Cytoskeletal Proteins

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Microscopy, Electron

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Spectrometry, Fluorescence

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Protein Conformation

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Mutation

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Models, Molecular

dc.title

Conformational changes of FtsZ reported by tryptophan mutants.

dc.type

Journal article

pubs.issue

21

pubs.organisational-group

School of Medicine

pubs.organisational-group

Duke

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Duke Cancer Institute

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Institutes and Centers

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Biochemistry

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Basic Science Departments

pubs.organisational-group

Cell Biology

pubs.publication-status

Published

pubs.volume

50

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