Expression of the bifunctional Bacillus subtilis TatAd protein in Escherichia coli reveals distinct TatA/B-family and TatB-specific domains.
Expression of the bifunctional Bacillus subtilis TatAd protein in Escherichia coli reveals distinct TatA/B-family and TatB-specific domains.
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双功能枯草芽孢杆菌 TatAd 蛋白在大肠杆菌中的表达揭示了不同的 TatA/B 家族和 TatB 特异性结构域。
DOI：
10.1007/s00203-011-0699-4
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发表时间：
2011
影响因子：
2.8
通讯作者：
Barnett JP
中科院分区：
文献类型：
--
作者：
Barnett JP
In the Tat protein export pathway of Gram-negative bacteria, TatA and TatB are homologous proteins that carry out distinct and essential functions in separate sub-complexes. In contrast, Gram-positive Tat systems usually lack TatB and the TatA protein is bifunctional. We have used a mutagenesis approach to delineate TatA/B-type domains in the bifunctional TatAd protein fromBacillus subtilis. This involved expression of mutated TatAd variants inEscherichia coliand tests to determine whether the variants could function as TatA or TatB by complementingE. colitatAand/ortatBmutants. We show that mutations in the C-terminal half of the transmembrane span and the subsequent FGP ‘hinge’ motif are critical for TatAd function with its partner TatCd subunit, and the same determinants are required for complementation of eithertatAortatBmutants inEscherichia coli. This is thus a critical domain in both TatA and TatB proteins. In contrast, substitution of a series of residues at the N-terminus specifically blocks the ability of TatAd to substitute forE. coliTatB. The results point to the presence of a universally conserved domain in the TatA/B-family, together with a separate N-terminal domain that is linked to the TatB-type function in Gram-negative bacteria.
