Direct homocysteine biosynthesis from O-succinylhomoserine in Escherichia coli: an alternate pathway that bypasses cystathionine
Direct homocysteine biosynthesis from O-succinylhomoserine in Escherichia coli: an alternate pathway that bypasses cystathionine
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大肠杆菌中 O-琥珀酰高丝氨酸直接生物合成同型半胱氨酸：绕过胱硫醚的替代途径
DOI：
10.1128/jb.153.1.558-561.1983
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发表时间：
1983
影响因子：
3.2
通讯作者：
JEN
中科院分区：
文献类型：
--
作者：
Marcia SIMONt;JEN
发现了使大肠杆菌K-12在没有胱硫醚酶的情况下形成同型半胱氨酸的突变。突变株中同型半胱氨酸的形成需要胱硫醚γ合成酶（metB基因产物），但绕过了正常的中间体胱硫醚。它的结论是，胱硫醚γ-合成酶催化形成同型半胱氨酸直接从O-琥珀酰高丝氨酸和一个尚未确定的硫供体。该突变显然导致这种硫供体的形成，并被命名为metQ。metQ基因的表达处于分解代谢物阻遏下。
Mutations were found which enable Escherichia coli K-12 to form homocysteine in the absence of cystathionase. The formation of homocysteine in the mutant strains required cystathionine gamma-synthetase, the metB gene product, but bypassed the normal intermediate cystathionine. It is concluded that cystathionine gamma-synthetase catalyzes the formation of homocysteine directly from O-succinylhomoserine and an as-yet-unidentified sulfur donor. The mutation apparently causes the formation of this sulfur donor and has been named metQ. The expression of the metQ gene is under catabolite repression.