Symbiobacterium Lost Carbonic Anhydrase in the Course of Evolution
Symbiobacterium Lost Carbonic Anhydrase in the Course of Evolution
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DOI：
10.1007/s00239-008-9191-4
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发表时间：
2009-01-01
影响因子：
3.9
通讯作者：
Ueda, Kenji
中科院分区：
文献类型：
--
作者：
Nishida, Hiromi;Beppu, Teruhiko;Ueda, Kenji
最近的遗传学研究已经阐明，碳酸酐酶（CA; EC 4.2.1.1），一种普遍存在的催化CO2和碳酸氢盐之间相互转化的酶，是环境空气下而不是高CO2空气下微生物生长所必需的。CA在原核生物基因组中的不规则分布表明其在原核生物中复杂的进化历史。本文研究了嗜热共生杆菌CA的遗传缺陷，嗜热共生杆菌是一种能在其他细菌产生的CO2上有效生长的互养细菌。基于31个核糖体蛋白质序列的系统发育分析表明共生菌属与梭菌属的隶属关系，具有100%的自举支持。β型和γ型CA在梭菌中的同源性支持了S。嗜热菌和一些相关的生物在进化过程中失去了这种酶。CA的损失可能是基于其生活环境中高水平的CO2的可用性。
Recent genetic studies have elucidated that carbonic anhydrase (CA; EC 4.2.1.1), a ubiquitous enzyme catalyzing interconversion between CO2 and bicarbonate, is essential for microbial growth under ambient air but not under high-CO2 air. The irregular distribution of the phylogenetically distinct types of CA in the prokaryotic genome suggests its complex evolutionary history in prokaryotes. This paper deals with the genetic defect of CA in Symbiobacterium thermophilum, a syntrophic bacterium that effectively grows on CO2 generated by other bacteria. Phylogenetic analysis based on 31 ribosomal protein sequences demonstrated the affiliation of Symbiobacterium with the class Clostridia with 100% bootstrap support. The phylogeny of beta- and gamma-type CA distributed among Clostridia supported the view that S. thermophilum and several related organisms lost this enzyme during the course of evolution. The loss of CA could be based on the availability of a high level of CO2 in their living environments.