（7-巯基庚酰基）磷酸苏氨酸的生物合成。

Biosynthesis of (7-mercaptoheptanoyl)threonine phosphate.

作者信息

White R H

机构信息

Department of Biochemistry and Anaerobic Microbiology, Virginia Polytechnic Institute, Blacksburg 24061-0308.

出版信息

Biochemistry. 1994 Jun 14;33(23):7077-81. doi: 10.1021/bi00189a009.

DOI:10.1021/bi00189a009

PMID:8003472

Abstract

The biosynthesis of (7-mercaptoheptanoyl)threonine phosphate (HS-HTP) has been studied in the methanogenic bacteria Methanococcus volta and Methanosarcina thermophila. Growth of these cells in medium containing [7,7-2H2]-7-mercaptoheptanoic acid, [3,4,4,4-threonine-2H4]-N-(7-mercaptoheptanoyl)threonine, [7,7-2H2]-N-(7-mercaptoheptanoyl)threonine, or DL-[3,4,4,4-2H4]threonine led to the generation of labeled HS-HTP containing a portion of the molecules with the same number of deuteriums as the precursor molecule. This result indicated that each of these labeled molecules can serve as a precursor for the biosynthesis of HS-HTP. Cell-free extracts of these methanogens were shown to carry out the ATP-dependent phosphorylation of N-(7-mercaptoheptanoyl)threonine to HS-HTP. These observations indicate that the biosynthesis of HS-HTP involves the coupling of mercaptoheptanoic acid with threonine to form (7-mercaptoheptanoyl)threonine, which is then phosphorylated to HS-HTP.

摘要

已在产甲烷菌沃氏甲烷球菌（Methanococcus volta）和嗜热甲烷八叠球菌（Methanosarcina thermophila）中研究了（7-巯基庚酰基）苏氨酸磷酸酯（HS-HTP）的生物合成。这些细胞在含有[7,7-2H₂]-7-巯基庚酸、[3,4,4,4-苏氨酸-2H₄]-N-（7-巯基庚酰基）苏氨酸、[7,7-2H₂]-N-（7-巯基庚酰基）苏氨酸或DL-[3,4,4,4-2H₄]苏氨酸的培养基中生长，导致生成标记的HS-HTP，其中一部分分子的氘原子数与前体分子相同。这一结果表明，这些标记分子中的每一个都可作为HS-HTP生物合成的前体。已证明这些产甲烷菌的无细胞提取物能将N-（7-巯基庚酰基）苏氨酸进行ATP依赖性磷酸化生成HS-HTP。这些观察结果表明，HS-HTP的生物合成涉及巯基庚酸与苏氨酸偶联形成（7-巯基庚酰基）苏氨酸，然后将其磷酸化生成HS-HTP。