Expression of the gap gene encoding glyceraldehyde-3-phosphate dehydrogenase of Streptomyces aureofaciens requires GapR, a member of the AraC/XylS family of transcriptional activators.
Expression of the gap gene encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is developmentally regulated, and induced by glucose in Streptomyces aureofaciens. A gene, gapR, encoding a protein similar to the AraC/XylS family of bacterial transcriptional regulators was identified upstream of gap. The gapR gene was constitutively expressed from a single promoter during the course of differentiation. By integrative transformation, via double crossover, a stable null mutant of the gapR gene was obtained. The mutation only slightly affected growth, and had no effect on differentiation of S. aureofaciens. However, transcription of the GAPDH-encoding gap gene was substantially reduced in the S. aureofaciens DeltagapR null mutant, irrespective of carbon source used. Though GAPDH activity was about 1.5-fold lower in the mutant, the substantial enzyme activity remained, suggesting the presence of a second GAPDH which is sufficient to ensure growth. The GapR protein, overproduced in Escherichia coli, was shown to bind upstream of the gap-P promoter region. The results indicate a direct role of GapR in regulation of gap expression in S. aureofaciens.
Sprušanský
O
O
Institute of Molecular Biology, Slovak Academy of Sciences, Dubravská cesta 21, 842 51 Bratislava, Slovak Republic1.
Řežuchová
B
B
Institute of Molecular Biology, Slovak Academy of Sciences, Dubravská cesta 21, 842 51 Bratislava, Slovak Republic1.
Homerová
D
D
Institute of Molecular Biology, Slovak Academy of Sciences, Dubravská cesta 21, 842 51 Bratislava, Slovak Republic1.
Kormanec
J
J
Institute of Molecular Biology, Slovak Academy of Sciences, Dubravská cesta 21, 842 51 Bratislava, Slovak Republic1.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D002454:Cell Differentiation; D018983:DNA Footprinting; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005797:Genes, araC; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000032:analysis; D013304:Streptomyces aureofaciens / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C435219:GapR protein, Streptomyces aureofaciens; D012333:RNA, Messenger; D015534:Trans-Activators; C078720:XylS protein, Pseudomonas putida; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases