Evolution of a chimeric mitochondrial carbonic anhydrase through gene fusion in a haptophyte alga
Evolution of a chimeric mitochondrial carbonic anhydrase through gene fusion in a haptophyte alga
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DOI：
10.1002/1873-3468.14475
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发表时间：
2022-08-30
期刊：
影响因子：
3.5
通讯作者：
Suzuki，Iwane
中科院分区：
文献类型：
--
作者：
Hirakawa，Yoshihisa;Hanawa，Yutaka;Suzuki，Iwane
碳酸酐酶（Carbonic anhydrase，CA）是一类催化二氧化碳和碳酸氢盐相互转化的酶家族，广泛分布于线粒体和质体等细胞中。到目前为止，已经表征了八类CA（α-、β-、γ-、δ-、ε-、η-、θ-和ι-CA）。本研究报告了一个有趣的基因编码的融合蛋白的β-CA和ι-CA中发现的haptophyteIsochrysis galbana。重组蛋白测定表明，C-末端i-CA区域催化CO2水合，而N-末端β-CA区域不再表现出酶活性。考虑到附着菌通常具有线粒体定位的β-CA和质体定位的1-CA，融合CA将显示中间阶段，其中在附着菌物种中线粒体β-CA被1-CA取代。
Carbonic anhydrases (CAs) are a universal enzyme family that catalyses the interconversion of carbon dioxide and bicarbonate, and they are localized in most compartments including mitochondria and plastids. Thus far, eight classes of CAs (α‐, β‐, γ‐, δ‐, ζ‐, η‐, θ‐ and ι‐CA) have been characterized. This study reports an interesting gene encoding a fusion protein of β‐CA and ι‐CA found in the haptophyteIsochrysis galbana. Recombinant protein assays demonstrated that the C‐terminal ι‐CA region catalyses CO2hydration, whereas the N‐terminal β‐CA region no longer exhibits enzymatic activity. Considering that haptophytes generally have mitochondrion‐localized β‐CAs and plastid‐localized ι‐CAs, the fusion CA would show an intermediate stage in which mitochondrial β‐CA is replaced by ι‐CA in a haptophyte species.