ribR基因编码一种单功能核黄素激酶，该激酶参与枯草芽孢杆菌核黄素操纵子的调控。

The ribR gene encodes a monofunctional riboflavin kinase which is involved in regulation of the Bacillus subtilis riboflavin operon.

作者信息

Solovieva I M, Kreneva R A, Leak D J, Perumov D A

机构信息

Department of Molecular and Radiation Biophysics, Petersburg Nuclear Physics Institute of the Russian Academy of Sciences, Gatchina, Leningrad District 188350, Russia.

Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AY, UK.

出版信息

Microbiology (Reading). 1999 Jan;145 ( Pt 1):67-73. doi: 10.1099/13500872-145-1-67.

DOI:10.1099/13500872-145-1-67

PMID:10206712

Abstract

A 3.5 kb EcoRI-BamHI fragment of Bacillus subtilis chromosomal DNA carrying the ribR gene, involved in regulation of the B. subtilis riboflavin operon, was cloned in the B. subtilis-Escherichia coli shuttle vector pCB20. DNA sequence analysis of this fragment revealed several ORFs, one of which encodes a polypeptide of 230 amino acids with up to 45% sequence identity with FAD synthetases from a number of micro-organisms, such as Corynebacterium ammoniagenes, E. coli and Pseudomonas fluorescens, and also to the ribC gene product of B. subtilis. The ribR gene was amplified by PCR, cloned and expressed in E. coli. Measurement of flavokinase activity in cell extracts demonstrated that ribR encodes a monofunctional flavokinase which converts riboflavin into FMN but not to FAD, and is specific for the reduced form of riboflavin.

摘要

携带参与枯草芽孢杆菌核黄素操纵子调控的ribR基因的枯草芽孢杆菌染色体DNA的一个3.5 kb EcoRI - BamHI片段，被克隆到枯草芽孢杆菌 - 大肠杆菌穿梭载体pCB20中。对该片段的DNA序列分析揭示了几个开放阅读框（ORF），其中一个编码一个230个氨基酸的多肽，与多种微生物（如产氨棒杆菌、大肠杆菌和荧光假单胞菌）的FAD合成酶具有高达45%的序列同一性，并且与枯草芽孢杆菌的ribC基因产物也有同一性。通过PCR扩增ribR基因，将其克隆并在大肠杆菌中表达。对细胞提取物中黄素激酶活性的测定表明，ribR编码一种单功能黄素激酶，它将核黄素转化为FMN而非FAD，并且对还原形式的核黄素具有特异性。