Van Spanning R J, van der Palen C J, Slotboom D J, Reijnders W N, Stouthamer A H, Duine J A
Department of Microbiology, BioCentrum Amsterdam, Vrije Universiteit, The Netherlands.
Eur J Biochem. 1994 Nov 15;226(1):201-10. doi: 10.1111/j.1432-1033.1994.tb20042.x.
Expression of methylamine dehydrogenase in Paracoccus denitrificans and its concomitant ability to grow on methylamine is regulated by a substrate-induction mechanism as well as by a catabolite-repression-like mechanism. Methylamine dehydrogenase is synthesized in cells growing on either methylamine or ethylamine, but not during growth on succinate, methanol or choline as sole sources of carbon and energy. The synthesis of methylamine dehydrogenase is repressed when succinate is added to the growth medium in addition to methylamine. Repression is not observed when the growth medium contains methylamine and either choline or methanol. Induction of the mau genes encoding methylamine dehydrogenase is under control of the mauR gene. This regulatory gene is located directly in front of, but with the transcription direction opposite to that of, the structural genes in the mau cluster. The mauR gene encodes a LysR-type transcriptional activator. Inactivation of the gene results in loss of the ability to synthesize methylamine dehydrogenase and amicyanin, and loss of the ability to grow on methylamine. The mutation is completely restored when the mauR gene is supplied in trans. The first gene of the cluster of mau genes that is under control of MauR is mauF, which encodes a putative membrane-embedded protein. Inactivation of the gene results in the inability of cells to grow on methylamine. Downstream from mauF and in the same transcription direction, mauB is located. This gene encodes the large subunit of methylamine dehydrogenase.
脱氮副球菌中甲胺脱氢酶的表达及其利用甲胺生长的伴随能力受底物诱导机制以及类似分解代谢物阻遏机制的调控。甲胺脱氢酶在以甲胺或乙胺为碳源和能源生长的细胞中合成，但在以琥珀酸、甲醇或胆碱作为唯一碳源和能源生长期间不合成。当除甲胺外还向生长培养基中添加琥珀酸时，甲胺脱氢酶的合成受到抑制。当生长培养基含有甲胺和胆碱或甲醇时，未观察到抑制现象。编码甲胺脱氢酶的mau基因的诱导受mauR基因的控制。该调控基因直接位于mau基因簇结构基因的前方，但转录方向与之相反。mauR基因编码一种LysR型转录激活因子。该基因的失活导致合成甲胺脱氢酶和含铜蓝蛋白的能力丧失，以及利用甲胺生长的能力丧失。当通过反式提供mauR基因时，该突变可完全恢复。受MauR控制的mau基因簇的第一个基因是mauF，它编码一种假定的膜嵌入蛋白。该基因的失活导致细胞无法利用甲胺生长。mauB位于mauF的下游且转录方向相同。该基因编码甲胺脱氢酶的大亚基。
