Fraser A D, Yamazaki H
Can J Microbiol. 1980 Mar;26(3):393-6. doi: 10.1139/m80-064.
The aerobic catabolism of glycerol depends on the expression of the glpK operon specifying a glycerol kinase and the glpD operon specifying an sn-glycerol-3-phosphate (G3P) dehydrogenase. It has not been clearly established how the expression of these operons is dependent on adenosine 3',5'-cyclic monophosphate (cAMP). We have isolated a promoterlike mutant (CA8306B) which, owing to a mutation in the glpK operon, can utilize glycerol in the absence of cAMP. Glycerol kinase and G3P dehydrogenase are inducible in CA8306B and its wild-type parent CA8000. The induced level of glycerol kinase in CA8306B is 30% that of CA8000 and this level is increased fivefold by the addition of cAMP. However, the induced level of G3P dehydrogenase in CA8306B is similar to that of CA8000 and is unaffected by cAMP addition. These results suggest that the promotion of the glpK operon requires cAMP whereas the promotion of the glpD operon does not.
甘油的有氧分解代谢取决于指定甘油激酶的glpK操纵子和指定sn-甘油-3-磷酸（G3P）脱氢酶的glpD操纵子的表达。这些操纵子的表达如何依赖于3'，5'-环磷酸腺苷（cAMP）尚未明确确定。我们分离出了一个类似启动子的突变体（CA8306B），由于glpK操纵子中的突变，它在没有cAMP的情况下能够利用甘油。甘油激酶和G3P脱氢酶在CA8306B及其野生型亲本CA8000中是可诱导的。CA8306B中甘油激酶的诱导水平是CA8000的30%，通过添加cAMP，这个水平会增加五倍。然而，CA8306B中G3P脱氢酶的诱导水平与CA8000相似，并且不受添加cAMP的影响。这些结果表明，glpK操纵子的激活需要cAMP，而glpD操纵子的激活则不需要。
