Kiyasu T, Nagahashi Y, Hoshino T
Department of Applied Microbiology, Nippon Roche Research Center, 200 Kajiwara, Kamakura, 247-8530, Kanagawa, Japan.
Gene. 2001 Mar 7;265(1-2):103-13. doi: 10.1016/s0378-1119(01)00354-7.
The biotin biosynthesis genes of Kurthia sp., which is an aerobic gram-positive bacterium, were cloned from Kurthia sp. 538-KA26 and characterized. Eleven biotin biosynthetic genes have been identified in Kurthia sp. Kurthia sp. has two genes coding for KAPA synthase, bioF and bioFII, and also has two genes coding for BioH protein, bioH and bioHII. In addition, three genes, orf1, orf2, and orf3, whose functions are unknown, were found in the biotin gene clusters of Kurthia sp. The bioA, bioD, and orf1 genes are arranged in a gene cluster in the order orf1bioDA, and the bioB, bioF, and orf2 genes are arranged in a gene cluster in the order orf2bioFB. These gene clusters proceed to both directions; the face to face promoters and two 40-bp of palindrome sequences exist upstream of the orf1 and orf2 genes. The bioC, bioFII, and bioHII genes are arranged in a gene cluster in the order bioFIIHIIC; a 40-bp of palindrome sequence exists upstream of the bioFII gene. The bioH and orf3 genes are arranged in a gene cluster in the order bioHorf3; a palindrome sequence was not found upstream of the bioH gene. These palindrome sequences are extremely similar to each other, suggesting that the orf1bioDA, orf2bioFB, and bioFIIHIIC gene clusters are regulated by biotin. Kurthia sp. does not have the bioW gene coding pimeloyl-CoA synthase, suggesting that pimeloyl-CoA may be produced by a different pathway than that of gram-positive bacterium B. subtilis or B. sphaericus, further suggesting a modified fatty acid synthesis pathway via acetyl-CoA instead as E. coli has.
库尔特氏菌属（Kurthia sp.）是一种需氧革兰氏阳性细菌，从库尔特氏菌属538 - KA26中克隆出其生物素生物合成基因并进行了表征。在库尔特氏菌属中已鉴定出11个生物素生物合成基因。库尔特氏菌属有两个编码KAPA合酶的基因，即bioF和bioFII，还有两个编码BioH蛋白的基因，即bioH和bioHII。此外，在库尔特氏菌属的生物素基因簇中发现了三个功能未知的基因，即orf1、orf2和orf3。bioA、bioD和orf1基因按orf1bioDA的顺序排列在一个基因簇中，bioB、bioF和orf2基因按orf2bioFB的顺序排列在一个基因簇中。这些基因簇向两个方向延伸；在orf1和orf2基因的上游存在面对面的启动子和两个40 bp的回文序列。bioC、bioFII和bioHII基因按bioFIIHIIC的顺序排列在一个基因簇中；在bioFII基因的上游存在一个40 bp的回文序列。bioH和orf3基因按bioHorf3的顺序排列在一个基因簇中；在bioH基因的上游未发现回文序列。这些回文序列彼此极其相似，表明orf1bioDA、orf2bioFB和bioFIIHIIC基因簇受生物素调控。库尔特氏菌属没有编码庚二酸单酰辅酶A合酶的bioW基因，这表明庚二酸单酰辅酶A的产生途径可能与革兰氏阳性细菌枯草芽孢杆菌或球形芽孢杆菌不同，进一步表明其脂肪酸合成途径可能像大肠杆菌一样通过乙酰辅酶A进行了修饰。
