ArgR-dependent Repression of Arginine and Histidine Transport Genes in Escherichia coli K-12

Caldara, Marina; Minh, Phu Nguyen Le; Bostoen, Sophie; Massant, Jan; Charlier, Daniël

doi:10.1016/j.jmb.2007.08.013

Cited by 42 publications

(56 citation statements)

References 67 publications

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“…The respective promoter- (Table 9). Consistent with earlier reports (8,9), the lac fusions with the promoters of hisJ, artJ, and artP exhibited repression by Arg in the wild-type strain and derepressed expression in a ⌬argR mutant (Table 9). EMSA experiments undertaken with the regulatory region of one of the genes, argT, revealed a very low affinity of binding by ArgP that was Lys independent (Fig.…”

supporting

confidence: 91%

Role of ArgP (IciA) in Lysine-Mediated Repression in Escherichia coli

Marbaniang

Gowrishankar

2011

J Bacteriol

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Initially identified as an inhibitor of oriC-initiated DNA replication in vitro, the ArgP or IciA protein of Escherichia coli has subsequently been described as a nucleoid-associated protein and also as a transcriptional regulator of genes involved in DNA replication (dnaA and nrdA) and amino acid metabolism (argO, dapB, and gdhA [the last in Klebsiella pneumoniae]). ArgP mediates lysine (Lys) repression of argO, dapB, and gdhA in vivo, for which two alternative mechanisms have been identified: at the dapB and gdhA regulatory regions, ArgP binding is reduced upon the addition of Lys, whereas at argO, RNA polymerase is trapped at the step of promoter clearance by Lys-bound ArgP. In this study, we have examined promoter-lac fusions in strains that were argP ؉ or ⌬argP or that were carrying dominant argP mutations in order to identify several new genes that are ArgP-regulated in vivo, including lysP, lysC, lysA, dapD, and asd (in addition to argO, dapB, and gdhA). All were repressed upon Lys supplementation, and in vitro studies demonstrated that ArgP binds to the corresponding regulatory regions in a Lys-sensitive manner (with the exception of argO, whose binding to ArgP was Lys insensitive). Neither dnaA nor nrdA was ArgP regulated in vivo, although their regulatory regions exhibited low-affinity binding to ArgP. Our results suggest that ArgP is a transcriptional regulator for Lys repression of genes in E. coli but that it is noncanonical in that it also exhibits low-affinity binding, without apparent direct regulatory effect, to a number of additional sites in the genome.

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confidence: 91%

Role of ArgP (IciA) in Lysine-Mediated Repression in Escherichia coli

Marbaniang

Gowrishankar

2011

J Bacteriol

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“…Furthermore, in all ARG box sequences there is absence of a guanine base at the T7 position (36). Another study has shown that replacement of T7 with G led to loss of ArgR repression at the promoter of hisJ (37). Substitution of the corresponding T7 (at Ϫ58) to G in the probable ARG box located within Ϫ64 to Ϫ47 in ybjE led to loss of ArgR repression of ybjElac (Table 2) and impaired the association of ArgR with the ybjE promoter DNA fragment bearing the above-mentioned base substitution (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…S2 in the supplemental material) located upstream of the core promoter elements. ArgR mediates repression of gene expression at hisJ and gltBDF in mechanistically distinct ways which in both cases are different from its mode of action on genes involved in Arg biosynthesis (37,47). It may be noted that for the gltBDF operon, hisJ, and genes involved in Arg biosynthesis, the absence of ArgR leads to derepression of gene expression, which is not the case for ybjE ( Table 2).…”

Section: Discussionmentioning

confidence: 99%

“…If this is true, then ybjE would represent yet another example where ArgR imparts gene repression by interacting with imperfect low-affinity ARG boxes. The cis regulatory regions of hisJ (37) and the gltBDF operon (47) contain imperfect ArgR binding sites (see Fig. S2 in the supplemental material) located upstream of the core promoter elements.…”

Section: Discussionmentioning

confidence: 99%

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Distinct Paths for Basic Amino Acid Export in Escherichia coli: YbjE (LysO) Mediates Export of l -Lysine

Pathania

Sardesai

2015

J Bacteriol

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In Escherichia coli, argO encodes an exporter for L-arginine (Arg) and its toxic analogue canavanine (CAN), and its transcriptional activation and repression, by Arg and L-lysine (Lys), respectively, are mediated by the regulator ArgP. Accordingly argO and argP mutants are CAN supersensitive (CAN ss IMPORTANCEThis work ascribes a lysine export function to the product of the ybjE gene of Escherichia coli, leading to a physiological scenario wherein two proteins, ArgO and YbjE, perform the task of separately exporting arginine and lysine, respectively, which is distinct from that seen for Corynebacterium glutamicum, where the ortholog of ArgO, LysE, mediates export of both arginine and lysine. Repression of argO transcription by lysine is thought to effect this separation. Accordingly, ArgO mediates lysine export when repression of its transcription by lysine is bypassed. Repression of ybjE transcription by arginine via the ArgR repressor, together with the lysine repression of argO effected by ArgP, is indicative of a mechanism of maintenance of arginine/lysine balance in E. coli. Bacteria possess membrane exporters for a variety of compounds. Their activities to a large extent are thought to play an adaptive role in mitigating the detrimental effects on bacterial growth caused by the presence of biotic stresses, such as those imposed by antibiotics, heavy metals, and other toxic compounds, in their natural environments. While it is easy to come to terms with the existence of proteins that mediate export of compounds described above, the presence of specific export systems for cellular metabolites such as sugars and amino acids appears somewhat enigmatic. For example, Escherichia coli encodes multiple proteins for the export of sugars, such as glucose and lactose (1), and for arabinose (2, 3). In addition, the occurrence of proteins mediating export of amino acids, such as alanine (4), arginine (5), aromatic amino acids (6), cysteine (7, 8), leucine (9), threonine (10, 11) and valine (12), in E. coli has been reported. While the physiological basis for the existence of amino acid exporters is not clear, their occurrence is relatively widespread in bacteria (13,14). It is thought that an amino acid exporter may serve to contribute to the fitness of an organism during conditions of metabolic imbalance resulting from excessive levels of its amino acid substrate in the cytoplasm (13,14). An alternative view could be that export of the amino acid occurs by chance, with the cognate substrate being a naturally occurring structurally related antimetabolite present in the environment. As an example of the latter, one mechanism contributing to the resistance of E. coli to the plant-derived antimetabolite canavanine (CAN), an L-arginine analogue, involves its export by ArgO, the ortholog of the basic amino acid exporter LysE of Corynebacterium glutamicum, following its uptake (5). Harnessing the amino acid export potential of a given bacterium has found widespread application in the commercial production of amin...

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“…Histidine transport has been intensively studied in the Gramnegative bacteria Escherichia coli, Salmonella enterica serovar Typhimurium, and Sinorhizobium meliloti, which adopt similar ABC transporters for histidine uptake (9)(10)(11). The well-understood high-affinity ABC-type histidine transporter of E. coli and S. Typhimurium consists of four components: the histidine-binding protein HisJ, the two membrane-bound proteins HisQ and HisM, and the ATPase HisP (10).…”

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confidence: 99%

Characterization and Molecular Mechanism of AroP as an Aromatic Amino Acid and Histidine Transporter in Corynebacterium glutamicum

Shang

Zhang

et al. 2013

Journal of Bacteriology

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bCorynebacterium glutamicum is equipped with abundant membrane transporters to adapt to a changing environment. Many amino acid transporters have been identified in C. glutamicum, but histidine uptake has not been investigated in detail. Here, we identified the aromatic amino acid transporter encoded by aroP as a histidine transporter in C. glutamicum by a combination of the growth and histidine uptake features. Characterization of histidine uptake showed that AroP has a moderate affinity for histidine, with a K m value of 11.40 ؎ 2.03 M, and histidine uptake by AroP is competitively inhibited by the aromatic amino acids. Among the four substrates, AroP exhibits a stronger preference for tryptophan than for tyrosine, phenylalanine, and histidine. Homology structure modeling and molecular docking were performed to predict the substrate binding modes and conformational changes during substrate transport. These results suggested that tryptophan is best accommodated in the binding pocket due to shape compatibility, strong hydrophobic interactions, and the lowest binding energy, which is consistent with the observed substrate preference of AroP. Furthermore, the missense mutations of the putative substrate binding sites verified that Ser24, Ala28, and Gly29 play crucial roles in substrate binding and are highly conserved in the Gram-positive bacteria. Finally, the expression of aroP is not significantly affected by extracellular histidine or aromatic amino acids, indicating that the physiological role of AroP may be correlated with the increased fitness of C. glutamicum to assimilate extracellular amino acid for avoiding the high energy cost of amino acid biosynthesis.

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ArgR-dependent Repression of Arginine and Histidine Transport Genes in Escherichia coli K-12

Cited by 42 publications

References 67 publications

Role of ArgP (IciA) in Lysine-Mediated Repression in Escherichia coli

Role of ArgP (IciA) in Lysine-Mediated Repression in Escherichia coli

Distinct Paths for Basic Amino Acid Export in Escherichia coli: YbjE (LysO) Mediates Export of l -Lysine

Characterization and Molecular Mechanism of AroP as an Aromatic Amino Acid and Histidine Transporter in Corynebacterium glutamicum

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