Regulation of AmtR-controlled gene expression in Corynebacterium glutamicum: mechanism and characterization of the AmtR regulon.
AmtR, the master regulator of nitrogen control in Corynebacterium glutamicum, represses transcription of a number of genes during nitrogen surplus. Repression is released by an interaction of AmtR with signal transduction protein GlnK. As shown by pull-down assays and gel retardation experiments, only adenylylated GlnK, which is present in the cells during nitrogen limitation, is able to bind to AmtR. The AmtR regulon was characterized in this study by a combination of bioinformatics, transcriptome and proteome analyses. At least 33 genes are directly controlled by the repressor protein including those encoding transporters and enzymes for ammonium assimilation (amtA, amtB, glnA, gltBD), urea and creatinine metabolism (urtABCDE, ureABCEFGD, crnT, codA), a number of biochemically uncharacterized enzymes and transport systems (NCgl1099, NCgl1100, NCgl 1915-1918) as well as signal transduction proteins (glnD, glnK). For the AmtR regulon, an AmtR box has been defined which comprises the sequence tttCTATN6AtAGat/aA. Furthermore, the transcriptional organization of AmtR-regulated genes and operons was characterized.
Beckers
Gabriele
G
Institut für Biochemie der Universität zu Köln, Zülpicher Str. 47, D-50674 Köln, Germany.
Strösser
Julia
J
Hildebrandt
Ulrich
U
Kalinowski
Jörn
J
Farwick
Mike
M
Krämer
Reinhard
R
Burkovski
Andreas
A
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D019295:Computational Biology / Q000379:methods; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D009584:Nitrogen / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome / Q000032:analysis; D018085:Regulon; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D014158:Transcription, Genetic
C414398:AmtR protein, Corynebacterium glutamicum; D001426:Bacterial Proteins; C113488:GlnK protein, Azorhizobium caulinodans; D020543:Proteome; D012097:Repressor Proteins; D009584:Nitrogen