The type IV secretion protein TraK from the Enterococcus conjugative plasmid pIP501 exhibits a novel fold
Conjugative plasmid transfer presents a serious threat to human health as the most important means of spreading antibiotic resistance and virulence genes among bacteria. The required direct cell–cell contact is established by a multi‐protein complex, the conjugative type IV secretion system (T4SS)....
Saved in:
Published in | Acta crystallographica. Section D, Biological crystallography. Vol. 70; no. 4; pp. 1124 - 1135 |
---|---|
Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
5 Abbey Square, Chester, Cheshire CH1 2HU, England
International Union of Crystallography
01.04.2014
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Conjugative plasmid transfer presents a serious threat to human health as the most important means of spreading antibiotic resistance and virulence genes among bacteria. The required direct cell–cell contact is established by a multi‐protein complex, the conjugative type IV secretion system (T4SS). The conjugative core complex spans the cellular envelope and serves as a channel for macromolecular secretion. T4SSs of Gram‐negative (G−) origin have been studied in great detail. In contrast, T4SSs of Gram‐positive (G+) bacteria have only received little attention thus far, despite the medical relevance of numerous G+ pathogens (e.g. enterococci, staphylococci and streptococci). This study provides structural information on the type IV secretion (T4S) protein TraK of the G+ broad host range Enterococcus conjugative plasmid pIP501. The crystal structure of the N‐terminally truncated construct TraKΔ was determined to 3.0 Å resolution and exhibits a novel fold. Immunolocalization demonstrated that the protein localizes to the cell wall facing towards the cell exterior, but does not exhibit surface accessibility. Circular dichroism, dynamic light scattering and size‐exclusion chromatography confirmed the protein to be a monomer. With the exception of proteins from closely related T4SSs, no significant sequence or structural relatives were found. This observation marks the protein as a very exclusive, specialized member of the pIP501 T4SS. |
---|---|
Bibliography: | ArticleID:AYD2MN5045 ark:/67375/WNG-5L724B6D-6 istex:67BD27D8DF2308851C9D223AB87F4A6253DCF265 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1399-0047 0907-4449 1399-0047 |
DOI: | 10.1107/S1399004714001606 |