Dispensabilities of Carbonic Anhydrase in Proteobacteria
Dispensabilities of Carbonic Anhydrase in Proteobacteria
复制标题
碳酸酐酶在变形菌中的必要性
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
T. Beppu
中科院分区：
文献类型：
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作者：
K. Ueda;H. Nishida;T. Beppu
碳酸酐酶 (CA) (E.C. 4.2.1.1) 是一种普遍存在的酶，可催化 CO2 和碳酸氢盐之间的相互转化。原核生物基因组中系统发育上不同的 CA 类别的不规则分布表明其在原核生物中复杂的进化历史。关于某些模式生物在高二氧化碳空气下 CA 的可分配性的遗传证据表明，缺乏 CA 的微生物可以通过选择高 CO2 生态位在自然环境中持续存在。在这项研究中，我们研究了 CA 在变形菌基因组中的分布。虽然大多数基因组测序的变形菌门保留了 CA 基因，但细胞内细菌属（例如 Buchnera 和 Rickettsia）含有 CA 缺陷菌株。保留CA和缺乏CA的基因组之间的比较表明，在一些菌株中不存在整个编码序列，而在其他菌株中存在移码编码序列。有证据表明，CA 在某些变形菌中由于其可有可无而在进化过程中失活并丢失。
Carbonic anhydrase (CA) (E.C. 4.2.1.1) is a ubiquitous enzyme catalysing interconversion between CO2 and bicarbonate. The irregular distribution of the phylogenetically distinct classes of CA in procaryotic genome suggests its complex evolutionary history in procaryotes. Genetic evidence regarding the dispensability of CA under high-CO2 air in some model organisms indicates that CA-deficient microorganisms can persist in the natural environment by choosing high-CO2 niches. In this study, we studied the distribution of CA in the genome of Proteobacteria. While a large majority of the genome-sequenced Proteobacteria retained a CA gene(s), intracellular bacterial genera such as Buchnera and Rickettsia contained CA-defective strains. Comparison between CA-retaining and CA- deficient genomes showed the absence of whole coding sequence in some strains and the presence of frameshifted coding sequence in other strains. The evidence suggests that CA is inactivated and lost in some proteobacteria during the course of evolution based on its dispensability.