变形链球菌菌株中葡糖基转移酶基因的分子分析。

Molecular analyses of glucosyltransferase genes among strains of Streptococcus mutans.

作者信息

Fujiwara T, Terao Y, Hoshino T, Kawabata S, Ooshima T, Sobue S, Kimura S, Hamada S

机构信息

Department of Pedodontics, Osaka University Faculty of Dentistry, Japan.

出版信息

FEMS Microbiol Lett. 1998 Apr 15;161(2):331-6. doi: 10.1111/j.1574-6968.1998.tb12965.x.

DOI:10.1111/j.1574-6968.1998.tb12965.x

PMID:9570124

Abstract

Three glucosyltransferase (GTase) genes (gtfB, gtfC and gtfD) were cloned and sequenced from clinically isolated strains of Streptococcus mutans MT8148 (serotype c), MT4239 (c), MT4245 (e), MT4467 (e) and MT4251 (f), respectively. Comparison of the gtf genes revealed that interstrain difference of gtfB and gtfD was limited, while gtfC showed significant interstrain variations. Similar to gtfB and gtfD, gtfC possessed five direct repeats composed of homologous unit in the carboxyl-terminal portion. The repeating unit consisted of 63-65 amino acid residues and is responsible for glucan binding. The gtfC gene from S. mutans MT4245 lacked the fourth unit. Multiple alignment with the gtf sequence of strain GS-5 (c) revealed several changes in these gtf genes due to frameshift mutations. The peptides encoded by the gtfB, gtfC and gtfD genes of GS-5 were 1, 80, and 32 amino acid residues shorter than those of the test strains except strain MT4245.

摘要

分别从变形链球菌临床分离株MT8148（血清型c）、MT4239（c）、MT4245（e）、MT4467（e）和MT4251（f）中克隆并测序了三个葡糖基转移酶（GTase）基因（gtfB、gtfC和gtfD）。对gtf基因的比较显示，gtfB和gtfD的菌株间差异有限，而gtfC表现出显著的菌株间变异。与gtfB和gtfD相似，gtfC在羧基末端部分拥有由同源单元组成的五个直接重复序列。重复单元由63 - 65个氨基酸残基组成，负责葡聚糖结合。变形链球菌MT4245的gtfC基因缺少第四个单元。与菌株GS - 5（c）的gtf序列进行多重比对发现，由于移码突变，这些gtf基因发生了一些变化。GS - 5的gtfB、gtfC和gtfD基因编码的肽段比除MT4245菌株外的测试菌株的肽段分别短1、80和32个氨基酸残基。