van den Bergh E R, Baker S C, Raggers R J, Terpstra P, Woudstra E C, Dijkhuizen L, Meijer W G
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, NN Haren, The Netherlands.
J Bacteriol. 1996 Feb;178(3):888-93. doi: 10.1128/jb.178.3.888-893.1996.
Xanthobacter flavus, a gram-negative facultatively autotrophic bacterium, employs the Calvin cycle for the fixation of carbon dioxide. Cells grown under autotrophic growth conditions possess an Fe(2+)-dependent fructosebisphosphate (FBP) aldolase (class II) in addition to a class I FBP aldolase. By nucleotide sequencing and heterologous expression in Escherichia coli, genes encoding transketolase (EC 2.2.1.1.; CbbT) and class II FBP aldolase (EC 4.1.2.13; CbbA) were identified. A partial open reading frame encoding a protein similar to pentose-5-phosphate 3-epimerase was identified downstream from cbbA. A phylogenetic tree of transketolase proteins displays a conventional branching order. However, the class II FBP aldolase protein from X. flavus is only distantly related to that of E. coli. The autotrophic FBP aldolase proteins from X. flavus, Alcaligenes eutrophus, and Rhodobacter sphaeroides form a tight cluster, with the proteins from gram-positive bacteria as the closest relatives.
黄杆菌属黄杆菌,一种革兰氏阴性兼性自养细菌,利用卡尔文循环固定二氧化碳。在自养生长条件下生长的细胞除了具有I类果糖二磷酸(FBP)醛缩酶外,还拥有一种铁(2+)依赖性果糖二磷酸(FBP)醛缩酶(II类)。通过核苷酸测序和在大肠杆菌中的异源表达,鉴定出了编码转酮醇酶(EC 2.2.1.1;CbbT)和II类FBP醛缩酶(EC 4.1.2.13;CbbA)的基因。在cbbA下游鉴定出了一个部分开放阅读框,其编码一种与戊糖-5-磷酸3-差向异构酶相似的蛋白质。转酮醇酶蛋白的系统发育树显示出传统的分支顺序。然而,黄杆菌属的II类FBP醛缩酶蛋白与大肠杆菌的该蛋白只有远缘关系。来自黄杆菌属、真养产碱菌和球形红杆菌的自养FBP醛缩酶蛋白形成一个紧密的簇,革兰氏阳性细菌的蛋白是其最亲近的亲属。