Analysis of YfgL and YaeT interactions through bioinformatics, mutagenesis, and biochemistry.
Analysis of YfgL and YaeT interactions through bioinformatics, mutagenesis, and biochemistry.
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通过生物信息学、诱变和生物化学分析 YfgL 和 YaeT 相互作用。
DOI：
10.1128/jb.01477-07
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发表时间：
2008
影响因子：
3.2
通讯作者：
Misra,Rajeev
中科院分区：
文献类型：
--
作者：
Vuong,Phu;Bennion,Drew;Mantei,Jeremy;Frost,Danielle;Misra,Rajeev
InEscherichia coli, YaeT, together with four lipoproteins, YfgL, YfiO, NlpB, and SmpA, forms a complex that is essential for β-barrel outer membrane protein biogenesis. Data suggest that YfgL and YfiO make direct but independent physical contacts with YaeT. Whereas the YaeT-YfiO interaction needs NlpB and SmpA for complex stabilization, the YaeT-YfgL interaction does not. Using bioinformatics, genetics, and biochemical approaches, we have identified three residues, L173, L175, and R176, in the mature YfgL protein that are critical for both function and interactions with YaeT. A single substitution at any of these sites produces no phenotypic defect, but two or three simultaneous alterations produce mild oryfgL-null phenotypes, respectively. Interestingly, biochemical data show that all YfgL variants, including those with single substitutions, have weakened in vivo YaeT-YfgL interaction. These defects are not due to mislocalization or low steady-state levels of YfgL. Cysteine-directed cross-linking data show that the region encompassing L173, L175, and R176 makes direct contact with YaeT. Using the same genetic and biochemical strategies, it was found that altering residues D227 and D229 in another region of YfgL from E221 to D229 resulted in defective YaeT bindings. In contrast, mutational analysis of conserved residues V319 to H328 of YfgL shows that they are important for YfgL biogenesis but not YfgL-YaeT interactions. The five YfgL mutants defective in YaeT associations and theyfgLbackground were used to show that SurA binds to YaeT (or another complex member) without going through YfgL.
