粘质沙雷氏菌ATCC21074中一个次要蛋白酶编码基因的克隆、测序及表达

Cloning, sequencing, and expression of a minor protease-encoding gene from Serratia marcescens ATCC21074.

作者信息

Kwon Y T, Lee H H, Rho H M

机构信息

Department of Molecular Biology, Seoul National University, Korea.

出版信息

Gene. 1993 Mar 15;125(1):75-80. doi: 10.1016/0378-1119(93)90748-r.

DOI:10.1016/0378-1119(93)90748-r

PMID:8449415

Abstract

The gene (smp) encoding an extracellular protease (Smp) from Serratia marcescens ATCC21074 has been cloned and expressed in Escherichia coli HB101. The nucleotide (nt) sequence of the cloned smp gene revealed a single open reading frame of 1056 bp coding for 352 amino acids (aa) (38,479 Da). The N-terminal aa sequence of Smp excreted from the E. coli host cells revealed that mature Smp consists of 300 aa (32,515 Da). The deduced aa sequence of Smp showed high overall homology (43%) to the Erwinia carotovora metalloprotease, but low homology (15-20%) to other metalloproteases, including the S. marcescens major metalloprotease. The location for three zinc ligands and the active site for Smp was predicted from other metalloproteases. The biochemical properties of Smp show that this enzyme is a metalloprotease whose activity is optimal at pH 8.0 and 50 degrees C.

摘要

编码粘质沙雷氏菌ATCC21074胞外蛋白酶（Smp）的基因（smp）已被克隆并在大肠杆菌HB101中表达。克隆的smp基因的核苷酸（nt）序列显示有一个1056 bp的单一开放阅读框，编码352个氨基酸（aa）（38,479 Da）。从大肠杆菌宿主细胞分泌的Smp的N端氨基酸序列显示，成熟的Smp由300个氨基酸（32,515 Da）组成。推导的Smp氨基酸序列与胡萝卜软腐欧文氏菌金属蛋白酶具有较高的总体同源性（43%），但与其他金属蛋白酶，包括粘质沙雷氏菌主要金属蛋白酶的同源性较低（15 - 20%）。根据其他金属蛋白酶预测了Smp的三个锌配体位置和活性位点。Smp的生化特性表明，该酶是一种金属蛋白酶，其活性在pH 8.0和50℃时最佳。