Richter G, Ritz H, Katzenmeier G, Volk R, Kohnle A, Lottspeich F, Allendorf D, Bacher A
Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Garching, Germany.
J Bacteriol. 1993 Jul;175(13):4045-51. doi: 10.1128/jb.175.13.4045-4051.1993.
GTP cyclohydrolase II catalyzes the first committed step in the biosynthesis of riboflavin. The gene coding for this enzyme in Escherichia coli has been cloned by marker rescue. Sequencing indicated an open reading frame of 588 bp coding for a 21.8-kDa peptide of 196 amino acids. The gene was mapped to a position at 28.2 min on the E. coli chromosome and is identical with ribA. GTP cyclohydrolase II was overexpressed in a recombinant strain carrying a plasmid with the cloned gene. The enzyme was purified to homogeneity from the recombinant strain. The N-terminal sequence determined by Edman degradation was identical to the predicted sequence. The sequence is homologous to the 3' part of the central open reading frame in the riboflavin operon of Bacillus subtilis.
GTP环化水解酶II催化核黄素生物合成中的首个关键步骤。通过标记拯救技术已克隆出大肠杆菌中编码该酶的基因。测序表明有一个588 bp的开放阅读框,编码一个由196个氨基酸组成的21.8 kDa肽段。该基因定位于大肠杆菌染色体上28.2分钟处的位置,与ribA相同。GTP环化水解酶II在携带含有克隆基因质粒的重组菌株中过表达。该酶从重组菌株中纯化至同质。通过埃德曼降解法测定的N端序列与预测序列相同。该序列与枯草芽孢杆菌核黄素操纵子中央开放阅读框的3'部分同源。