Open AccessConversion of the coprogen transport protein FhuE and the ferrioxamine B transport protein FoxA into ferrichrome transport proteins
Author(s) -
Killmann Helmut,
Braun Volkmar
Publication year - 1998
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.1574-6968.1998.tb12929.x
Subject(s) - ferrichrome , colicin , biology , transport protein , escherichia coli , bacterial outer membrane , biochemistry , two hybrid screening , gene
The FhuA protein of Escherichia coli K‐12 transports ferrichrome and the structurally related antibiotic albomycin across the outer membrane and serves as a receptor for the phages T1, T5, and φ80 and for colicin M. In this paper, we show that chimeric proteins consisting of the central part of FhuA and the N‐ and C‐terminal parts of FhuE (coprogen receptor) or the N‐ and/or C‐terminal parts of FoxA (ferrioxamine B receptor), function as ferrichrome transport proteins. Although the hybrid proteins contained the previously identified gating loop of FhuA, which is the principal binding site of the phages T5, T1, and φ80, only the hybrid protein consisting of the N‐terminal third of FoxA and the C‐terminal two thirds of FhuA conferred weak phage sensitivity to cells. Apparently, the gating loop is essential, but not sufficient for wild‐type levels of ferrichrome transport and for phage sensitivity. The properties of FhuA‐FoxA hybrids suggest different regions of the two receptors for ferric siderophore uptake.