Scott A I
Department of Chemistry, Texas A&M University, College Station 77843-3255.
Ciba Found Symp. 1994;180:285-303; discussion 303-8. doi: 10.1002/9780470514535.ch16.
The acquisition and sequencing of the genes encoding the enzymes for vitamin B12 biosynthesis in Salmonella typhimurium and Pseudomonas denitrificans has dramatically altered the direction of research on the pathway from uroporphyrinogen III to the corrinoids. Through a combination of molecular biology, organic chemistry and NMR spectroscopy, logical progression along the sequence is being made. Recent work from our laboratory is focused on the discovery and specificities of the methyltransferases connecting uroporphyrinogen III with cobyrinic acid, the temporal resolution of cobalt insertion and a comparison of the anaerobic pathway in S. typhimurium and the aerobic pathway in Ps. denitrificans. The implication of two parallel routes to corrins in these bacteria is discussed.
鼠伤寒沙门氏菌和反硝化假单胞菌中编码维生素B12生物合成酶的基因的获取与测序，极大地改变了从尿卟啉原III到类咕啉途径的研究方向。通过分子生物学、有机化学和核磁共振光谱学的结合，正沿着该序列进行逻辑推进。我们实验室最近的工作集中在连接尿卟啉原III与钴胺酸的甲基转移酶的发现和特异性、钴插入的时间分辨率以及鼠伤寒沙门氏菌厌氧途径与反硝化假单胞菌需氧途径的比较。讨论了这些细菌中两条平行的咕啉合成途径的意义。
