Structure and sequence divergence of two archaebacterial genes.
Structure and sequence divergence of two archaebacterial genes.
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两个古细菌基因的结构和序列差异。
DOI：
10.1073/pnas.82.12.4207
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发表时间：
1985
影响因子：
11.1
通讯作者：
Konisky,J
中科院分区：
文献类型：
--
作者：
Cue,D;Beckler,GS;Reeve,JN;Konisky,J
比较了两种相关产甲烷古细菌——伏特产甲烷球菌和凡尼产甲烷球菌的hisA基因所在区域的DNA序列。这两个生物在这个区域显示出相似的基因组组织，显示出三个开放阅读框（orf），由非常高的a + T含量区域分开。两个orf，包括ORFHisA，显示出显著的DNA序列同源性。正如我们所预料的那样，对于基因组富含a + t的生物体来说，密码子的第三个碱基是a和U。虽然结构基因上游的区域含有类似原核生物的启动子序列，但尚不清楚它们是否在这些古细菌细胞中被识别为启动子。核糖体结合位点G-G-T-G位于两个hisA基因的ATG翻译起始序列之前6个碱基对。两个hisA基因的上游序列仅显示有限的序列同源性。M. voltae基因间区包含4个串联排列的11碱基对序列，而M. vannielii基因间区包含直接和反向重复序列。基于hisA序列的同源性，我们得出结论，M. voltae和M. vannielii在分类上的亲缘关系不如真细菌肠道群的成员。
The DNA sequences of a region that includes the hisA gene of two related methanogenic archaebacteria, Methanococcus voltae and Methanococcus vannielii, have been compared. Both organisms show a similar genome organization in this region, displaying three open reading frames (ORFs) separated by regions of very high A + T content. Two of the ORFs, including ORFHisA, show significant DNA sequence homology. As might be expected for organisms having a genome that is A + T-rich, there is a high preference for A and U as the third base in codons. Although the regions upstream of the structural genes contain prokaryotic-like promoter sequences, it is not known whether they are recognized as promoters in these archaebacterial cells. A ribosome binding site, G-G-T-G, is located 6 base pairs preceding the ATG translation initiation sequence of both hisA genes. The sequences upstream of the two hisA genes show only limited sequence homology. The M. voltae intergenic region contains four tandemly arranged repetitions of an 11-base-pair sequence, whereas the M. vannielii sequence contains both direct and inverted repetitive sequences. Based on the degree of hisA sequence homology, we conclude that M. voltae and M. vannielii are less closely related taxonomically than are members of the enteric group of eubacteria.