2010年11月
Cadaverine Covalently Linked to Peptidoglycan Is Required for Interaction between the Peptidoglycan and the Periplasm-Exposed S-Layer-Homologous Domain of Major Outer Membrane Protein Mep45 in Selenomonas ruminantium
JOURNAL OF BACTERIOLOGY
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- 巻
- 192
- 号
- 22
- 開始ページ
- 5953
- 終了ページ
- 5961
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1128/JB.00417-10
- 出版者・発行元
- AMER SOC MICROBIOLOGY
The peptidoglycan of Selenomonas ruminantium is covalently bound to cadaverine (PG-cadaverine), which likely plays a significant role in maintaining the integrity of the cell surface structure. The outer membrane of this bacterium contains a 45-kDa major protein (Mep45) that is a putative peptidoglycan-associated protein. In this report, we determined the nucleotide sequence of the mep45 gene and investigated the relationship between PG-cadaverine, Mep45, and the cell surface structure. Amino acid sequence analysis showed that Mep45 is comprised of an N-terminal S-layer-homologous (SLH) domain followed by alpha-helical coiled-coil region and a C-terminal beta-strand-rich region. The N-terminal SLH domain was found to be protruding into the periplasmic space and was responsible for binding to peptidoglycan. It was determined that Mep45 binds to the peptidoglycan in a manner dependent on the presence of PG-cadaverine. Electron microscopy revealed that defective PG-cadaverine decreased the structural interactions between peptidoglycan and the outer membrane, consistent with the proposed role for PG-cadaverine. The C-terminal beta-strand-rich region of Mep45 was predicted to be a membrane-bound unit of the 14-stranded beta-barrel structure. Here we propose that PG-cadaverine possesses functional importance to facilitate the structural linkage between peptidoglycan and the outer membrane via specific interaction with the SLH domain of Mep45.
- リンク情報
- ID情報
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- DOI : 10.1128/JB.00417-10
- ISSN : 0021-9193
- Web of Science ID : WOS:000283559300012