%0 Journal Article
%T Minimal functional domain of cytidine 5''-monophosphate N-acetylneuraminic acid (CMP-NeuAc) synthetase from Escherichia coli]<br>大肠杆菌CMP-唾液酸合成酶最小活性域的研究
%A JIN Chun-Sheng
%A JIN Cheng
%A <br>金春生
%A 金城
%J 生物工程学报
%D 2002
%I 
%X In comparison with its counterpart from N.meningitides, all conserved motifs were found in the N-termini of E.coli CMP-NeuAc synthetase. E.coli CMP-NeuAc synthetase seems to have redundant C-termini with a less effect on its activity. To explain this speculation, a series of recombinant DNAs with deletion from 3'-end of CMP-NeuAc synthetase were produced by PCR, ligated into expression vector pET-15b and expressed in BL21(DE3)pLysS. After induction with IPTG, we found that the recombinant enzyme with deletion of 189 amino acids from C-termini retained its activity. This result demonstrates that the 229 amino acids of N-termini was the minimal functional domain of E.coli CMP-NeuAc synthetase. The deletions altered the optimum pH and thermostability of active truncated enzymes, indicating that the truncated C-terminal amino acids of E.coli CMP-NeuAc synthetase could affect the conformation of the enzymatic catalytic domain and therefore affect its catalytic activity and thermostability, although it is not involved in enzymatic activity directly.
%K sialic acid
%K CMP-NeuAc synthetase
%K deletion<br>大肠杆菌
%K CMP－唾液酸合成酶
%K 最小活性域
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=A66E90C274451689E69F6F0291467824&aid=6B57A6EC104DBFD3&yid=C3ACC247184A22C1&vid=13553B2D12F347E8&iid=B31275AF3241DB2D&sid=5AE7FA263C8A6D65&eid=6D25DD85174CF6DB&journal_id=1000-3061&journal_name=生物工程学报&referenced_num=0&reference_num=13