A third periplasmic transport system for l‐arginine in Escherichia coli: molecular characterization of the artPIQMJ genes, arginine binding and transport

Abstract

A new binding-protein-dependent transport system of Escherichia coli specific for L-arginine was characterized by genetic and biochemical means. The system is encoded by five adjacent genes, artPIQMJ (art standing for arginine transport), which are organized in two transcriptional units (artPIQM and artJ). The artl and artJ gene products (Artl and ArtJ) are periplasmic binding proteins with sequence similarity to binding proteins for polar (basic) amino acids. The artQ, artM and artP products are similar to the transmembraneous proteins and the ATPase of binding-protein-dependent carriers. The mature Artl and J proteins were localized in the periplasm and lacked signal peptides of 19 amino acid residues. Artl and ArtJ were isolated from overproducing strains. ArtJ specifically binds L-arginine with high affinity and overproduction of ArtJ stimulated L-arginine uptake by the bacteria. The substrate for Artl is not known, and isolated Artl did not bind common amino acids, various basic uncommon amino acids or amines. It is concluded that the artPIQM artJ genes encode a third arginine-uptake system in addition to the known argT hisJQMP system of Salmonella typhimurium and E. coli and the arginine (-ornithine) carrier (aps) of E. coli.

Global Gene Expression Profiling in Escherichia coliK12

“…artP and artI are involved in arginine transport (32). The expression of these genes is increased in the lrp Ϫ strain 6.3-and 4.6-fold, respectively.…”

“…The rpoE gene encodes another sigma element, 24 , that also is expressed at a higher level in the lrp Ϫ strain. Although the major functions of coping with thermal stress are encoded by genes transcribed by 32 , genes transcribed by 24 are necessary for survival under extreme temperature stress conditions (65). Interestingly, although the expression level of the rpoH gene for 32 is unaffected in the lrp Ϫ strain, several genes regulated by this sigma factor, such as dnaK, dnaJ, clpA, clpB, clpP.…”

“…Although the major functions of coping with thermal stress are encoded by genes transcribed by 32 , genes transcribed by 24 are necessary for survival under extreme temperature stress conditions (65). Interestingly, although the expression level of the rpoH gene for 32 is unaffected in the lrp Ϫ strain, several genes regulated by this sigma factor, such as dnaK, dnaJ, clpA, clpB, clpP. htpG, htpX, gapA, and grpE, 3 all exhibit 2-3-fold increased expression levels in the lrp Ϫ strain.…”

Identification of the gene responsible for the cblA complementation group of vitamin B 12 -responsive methylmalonic acidemia based on analysis of prokaryotic gene arrangements

“…The LAO͞AO and arginine periplasmic binding proteins have been shown to be associated with two independent inner membrane transport systems, HisP and ArtP. Both are ATPases with ATP-binding cassette signatures (24,25). This challenges the notion that ArgK, which lacks an ATP-binding cassette signature, is an LAO͞AO transport-associated ATPase.…”

Metabolic Context and Possible Physiological Themes of ς54-Dependent Genes inEscherichia coli

“…The second 54 -independent system consists of the artPIQM-artJ operons, which are at min 19 of the E. coli chromosome (169). ArtJ is a periplasmic protein that binds arginine but not ornithine (169). ArtI is another putative periplasmic binding protein, but it does not detectably bind any amino acid.…”