Simpson C L, Russell R R
Department of Oral Biology, The Dental School, University of Newcastle upon Tyne, United Kingdom.
Infect Immun. 1998 May;66(5):2085-92. doi: 10.1128/IAI.66.5.2085-2092.1998.
A locus containing a gene with homology to ccpA of other bacteria has been cloned from Streptococcus mutans LT11, sequenced, and named regM. Upstream of the regM gene, on the opposite strand, is a gene encoding an X-Pro dipeptidase, pepQ. A 14-bp palindromic sequence with homology to the consensus catabolite-responsive element sequence lay in the promoter region between the two genes. To study the function of regM, the gene was inactivated by insertion of an antibiotic resistance marker. Diauxic growth of S. mutans on a number of sugars in the presence of glucose was not affected by disruption of regM. The loss of RegM increased glucose repression of alpha-galactosidase, mannitol-1-P dehydrogenase, and P-beta-galactosidase activities. These results suggest that while RegM can affect catabolite repression in S. mutans, it does not conform to the model proposed for CcpA in Bacillus subtilis.
已从变形链球菌LT11中克隆出一个与其他细菌的ccpA具有同源性的基因所在的基因座,进行了测序,并命名为regM。在regM基因的上游,位于相反链上的是一个编码X-Pro二肽酶pepQ的基因。在这两个基因之间的启动子区域存在一个与共有分解代谢物反应元件序列具有同源性的14bp回文序列。为了研究regM的功能,通过插入抗生素抗性标记使该基因失活。在葡萄糖存在的情况下,变形链球菌在多种糖类上的双相生长不受regM破坏的影响。RegM的缺失增加了α-半乳糖苷酶、甘露醇-1-P脱氢酶和P-β-半乳糖苷酶活性的葡萄糖阻遏作用。这些结果表明,虽然RegM可以影响变形链球菌中的分解代谢物阻遏,但它不符合枯草芽孢杆菌中CcpA所提出的模型。