Pannekoek Yvonne, Heurgué-Hamard Valérie, Langerak Ankie A J, Speijer Dave, Buckingham Richard H, van der Ende Arie
Academic Medical Center, Dept. of Medical Microbiology, Room L1-162, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, The Netherlands.
J Bacteriol. 2005 Jan;187(2):507-11. doi: 10.1128/JB.187.2.507-511.2005.
The gene prmC, encoding the putative S-adenosyl-L-methionine (AdoMet)-dependent methyltransferase (MTase) of release factors (RFs) of the obligate intracellular pathogen Chlamydia trachomatis, was functionally analyzed. Chlamydial PrmC expression suppresses the growth defect of a prmC knockout strain of Escherichia coli K-12, suggesting an interaction of chlamydial PrmC with E. coli RFs in vivo. In vivo methylation assays carried out with recombinant PrmC and RFs of chlamydial origin demonstrated that PrmC methylates RFs within the tryptic fragment containing the universally conserved sequence motif Gly-Gly-Gln. This is consistent with the enzymatic properties of PrmC of E. coli origin. We conclude that C. trachomatis PrmC functions as an N5-glutamine AdoMet-dependent MTase, involved in methylation of RFs.
对编码专性胞内病原体沙眼衣原体释放因子(RFs)假定的依赖S-腺苷-L-甲硫氨酸(AdoMet)的甲基转移酶(MTase)的基因prmC进行了功能分析。衣原体PrmC的表达抑制了大肠杆菌K-12的prmC基因敲除菌株的生长缺陷,这表明衣原体PrmC在体内与大肠杆菌RFs存在相互作用。用重组PrmC和衣原体来源的RFs进行的体内甲基化试验表明,PrmC使包含普遍保守序列基序甘氨酸-甘氨酸-谷氨酰胺的胰蛋白酶片段内的RFs发生甲基化。这与大肠杆菌来源的PrmC的酶学特性一致。我们得出结论,沙眼衣原体PrmC作为一种依赖N5-谷氨酰胺AdoMet的MTase发挥作用,参与RFs的甲基化。