Sequence Analysis of the Streptococcus mutans Ingbritt dexA Gene Encoding Extracellular Dextranase
Sequence Analysis of the Streptococcus mutans Ingbritt dexA Gene Encoding Extracellular Dextranase
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变形链球菌 Ingbritt dexA 胞外葡聚糖酶基因的序列分析
DOI：
10.1111/j.1348-0421.1995.tb03282.x
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发表时间：
1995
影响因子：
2.6
通讯作者：
N. Goto
中科院分区：
文献类型：
--
作者：
T. Igarashi;A. Yamamoto;N. Goto
测定了变形链球菌Ingbritt(血清型c)的葡聚糖酶基因(DEXA)的全序列(3,747bp)和染色体侧翼区。DEXA的开放阅读框为2550bp，以终止密码子TGA结尾。确定了一个假定的核糖体结合位点、起始密码子之前的启动子和潜在的茎环结构。推测的葡聚糖酶蛋白(DEXA)由850个氨基酸组成，分子大小为94,536 Da，等电点为4.79。变形链球菌DEXA的核苷酸序列和推导的氨基酸序列与远缘链球菌的同源性分别为57.8%和47.0%。远缘链霉菌Dex基因的同源区位于N-末端。DEXA的C末端由一个六肽LPQTGD六肽组成，其次是7个带电荷的氨基酸，21个氨基酸具有很强的疏水性，以及一个带电的六肽尾巴，这些结构不仅是革兰氏阳性球菌表面相关蛋白的共同结构，也是变形链球菌的β-果糖苷酶和远缘链球菌的葡聚糖酶等胞外酶的共同结构。DEXA蛋白与葡萄糖基转移酶、葡聚糖结合蛋白或变形链球菌的葡聚糖酶抑制剂没有明显的同源性。
The complete nucleotide sequence (3,747 bp) of the dextranase gene (dexA) and flanking regions of the chromosome of Streptococcus mutans Ingbritt (serotype c) were determined. The open reading frame for dexA was 2,550 bp, ending with a stop codon TGA. A putative ribosome‐binding site, promoter preceding the start codon, and potential stem‐loop structure were identified. The presumed dextranase protein (DexA) consisting of 850 amino acids was estimated to have a molecular size of 94,536 Da and a pI of 4.79. The nucleotide sequence and the deduced amino acid sequences of S. mutans dexA exhibited homologies of 57.8% and 47.0%, respectively, to those of Streptococcus sobrinus dex. The homologous region of dex of S. sobrinus was in the N‐terminal half. The C terminus of DexA consisted of a hexapeptide LPQTGD, followed by 7 charged amino acids, 21 amino acids with a strongly hydrophobic character, and a charged hexapeptide tail, which have been reported as a common structure of C termini of not only the surface‐associated proteins of Gram‐positive cocci but also the extracellular enzymes such as β‐fructosidase of S. mutans and dextranase of S. sobrinus. The DexA protein had no significant homology with the glucosyltransferases, the glucan‐binding protein, or the dextranase inhibitor of mutans streptococci.
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影响因子：
3.5
作者：
Shunsaku Ueda;T. Shiroza;Howard K. Kuramitsu
通讯作者：
Shunsaku Ueda;T. Shiroza;Howard K. Kuramitsu
影响因子：
2.8
作者：
COLBY, SM;WHITING, GC;RUSSELL, RRB
通讯作者：
RUSSELL, RRB
A 组链球菌 6 M 型蛋白的完整核苷酸序列。
DOI：
--
发表时间：
1986
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Hollingshead,SK;Fischetti,VA;Scott,JR
通讯作者：
Scott,JR
DOI：
10.1099/00221287-136-5-803
发表时间：
1990-05
期刊：
Journal of general microbiology
影响因子：
--
作者：
R. Russell;J. Ferretti
通讯作者：
R. Russell;J. Ferretti
DOI：
10.1099/00221287-139-9-2019
发表时间：
1993-09
期刊：
Journal of general microbiology
影响因子：
--
作者：
G. C. Whiting;I. Sutcliffe;R. Russell
通讯作者：
G. C. Whiting;I. Sutcliffe;R. Russell