Open AccessFunctional substitution of the transient membrane‐anchor domain in Escherichia coli FtsY with an N‐terminal hydrophobic segment of Streptomyces lividans FtsY
Author(s) -
Maeda Isamu,
Hirata Asumi,
Shoji Miki,
Ueda Shunsaku,
Yoshida Kazuyuki
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2008.01297.x
Subject(s) - signal recognition particle , biology , escherichia coli , fusion protein , membrane protein , biochemistry , signal peptide , cytoplasm , mutant , signal recognition particle receptor , protein targeting , microbiology and biotechnology , peptide sequence , gene , membrane , recombinant dna
FtsY is a signal recognition particle receptor in Escherichia coli that mediates the targeting of integral membrane proteins to translocons by interacting with both signal recognition particle (SRP)‐nascent polypeptide–ribosome complexes and the cytoplasmic membrane. Genes encoding the N‐terminal segments of Streptomyces lividans FtsY were fused to a gene encoding the E. coli FtsY NG domain (truncated versions of FtsY lacking the transient membrane‐anchor domain at the N‐terminus), introduced into a conditional ftsY ‐deletion mutant of E. coli , and expressed in trans to produce chimeric FtsY proteins. Under FtsY‐depleted conditions, strains producing chimeric proteins including 34 N‐terminal hydrophobic residues grew whereas strains producing chimeric proteins without these 34 residues did not. A strain producing the chimeric protein comprising the 34 residues and NG domain processed β‐lactamase, suggesting that the SRP‐dependent membrane integration of leader peptidase was restored in this strain. These results suggest that the N‐terminal hydrophobic segment of FtsY in this Gram‐positive bacterium is responsible for its interaction with the cytoplasmic membrane.