Substrate induction and glucose repression of maltose utilization by Streptomyces coelicolor A3(2) is controlled by malR, a member of the lacl-galR family of regulatory genes.
malR of Streptomyces coelicolor A3(2) encodes a homologue of the Lacl/GalR family of repressor proteins, and is divergently transcribed from the malEFG gene cluster, which encodes components of an ATP-dependent transport system that is required for maltose utilization. Transcription of malE was induced by maltose and repressed by glucose. Disruption or deletion of malR resulted in constitutive, glucose-insensitive malE transcription at a level markedly above that observed in the parental malR+ strain, and overproduction of MalR prevented growth on maltose as carbon source. Consequently, MalR plays a crucial role in both substrate induction and glucose repression of maltose utilization. malR is expressed from a single promoter with transcription initiating at the first G of the predicted GTG translation start codon.
van Wezel
G P
GP
John Innes Centre, Norwich Research Park, Colney, Norwich, UK.
White
J
J
Young
P
P
Postma
P W
PW
Bibb
M J
MJ
D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000378:metabolism; D001426:Bacterial Proteins; D001483:Base Sequence; D006224:Cricetinae; D004247:DNA / Q000302:isolation & purification / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D005809:Genes, Regulator; D008320:Maltose / Q000378:metabolism*; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000235:genetics*; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D015533:Transcriptional Activation / Q000502:physiology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D012097:Repressor Proteins; C084528:malR protein, bacteria; D008320:Maltose; D004247:DNA