Isolation of DNA encoding sucrase genes from Streptococcus salivarius and partial characterization of the enzymes expressed in Escherichia coli
Isolation of DNA encoding sucrase genes from Streptococcus salivarius and partial characterization of the enzymes expressed in Escherichia coli
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从唾液链球菌中分离编码蔗糖酶基因的 DNA 并对大肠杆菌中表达的酶进行部分表征
DOI：
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发表时间：
1987
影响因子：
3.2
通讯作者：
J. Perchorowicz
中科院分区：
文献类型：
--
作者：
C. Houck;J. Pear;R. Elliott;J. Perchorowicz
含有两个蔗糖酶基因的限制性酶片段已从唾液链球菌 DNA 粘粒文库中分离出来。这些基因在大肠杆菌细胞中表达，并在大肠杆菌部分纯化的蛋白质提取物中研究了两种酶的特性。将一个编码转化酶型蔗糖酶的基因亚克隆到 2.4 千碱基对片段上。该蔗糖酶对蔗糖的 Km 为 48 mM，最适 pH 值为 6.5。唾液链球菌蔗糖酶克隆未显示出与酵母转化酶克隆的可检测的杂交。两个具有 1 KB 对 DNA 共同点的重叠亚克隆被用来定位果糖基转移酶基因。果糖基转移酶的 Km 为 93 mM，最适 pH 为 7.0。果糖基转移酶的产物是果聚糖。来自枯草芽孢杆菌的果糖基转移酶克隆不与唾液链球菌 DNA 杂交。将酶的特性与先前表征的蔗糖酶的特性进行比较。
Restriction enzyme fragments containing two sucrase genes have been isolated from a cosmid library of Streptococcus salivarius DNA. The genes were expressed in Escherichia coli cells, and the properties of both enzymes were studied in partially purified protein extracts from E. coli. One gene encoding an invertase-type sucrase was subcloned on a 2.4-kilobase-pair fragment. The sucrase enzyme had a Km for sucrose of 48 mM and a pH optimum of 6.5. The S. salivarius sucrase clone showed no detectable hybridization to a yeast invertase clone. Two overlapping subclones which had 1 kilobase pair of DNA in common were used to localize a fructosyltransferase gene. The fructosyltransferase had a Km of 93 mM and a pH optimum of 7.0. The product of the fructosyltransferase was a levan. A fructosyltransferase clone from Bacillus subtilis did not hybridize to S. salivarius DNA. The properties of the enzymes were compared with those of previously characterized sucrases.
影响因子：
2.6
作者：
KNAUF, VC;NESTER, EW
通讯作者：
NESTER, EW