Song Jung Min, Hong Seung Kon, An Young Jun, Kang Mee Hye, Hong Kwon Ho, Lee Youn-Ho, Cha Sun-Shin
Korea Institute of Ocean Science and Technology , 787 Haean-Ro, Sangnok-Gu, Ansan 426-744, Republic of Korea.
Department of Chemistry & Nano Science, Ewha Womans University , Seoul 03760, Republic of Korea.
J Agric Food Chem. 2017 Mar 1;65(8):1630-1640. doi: 10.1021/acs.jafc.6b05037. Epub 2017 Feb 16.
The CaCel gene from Antarctic springtail Cryptopygus antarcticus codes for a cellulase belonging to the glycosyl hydrolase family 45 (GHF45). Phylogenetic, biochemical, and structural analyses revealed that the CaCel gene product (CaCel) is closely related to fungal GHF45 endo-β-1,4-glucanases. The organization of five introns within the open reading frame of the CaCel gene indicates its endogenous origin in the genome of the species, which suggests the horizontal transfer of the gene from fungi to the springtail. CaCel exhibited optimal activity at pH 3.5, retained 80% of its activity at 0-10 °C, and maintained a half-life of 4 h at 70 °C. Based on the structural comparison between CaCel and a fungal homologue, we deduced the structural basis for the unusual characteristics of CaCel. Under acidic conditions at 50 °C, CaCel was effective to digest the green algae (Ulva pertusa), suggesting that it could be exploited for biofuel production from seaweeds.
来自南极跳虫南极隐跳虫的CaCel基因编码一种属于糖基水解酶家族45（GHF45）的纤维素酶。系统发育、生化和结构分析表明，CaCel基因产物（CaCel）与真菌GHF45内切-β-1,4-葡聚糖酶密切相关。CaCel基因开放阅读框内五个内含子的组织表明其在该物种基因组中的内源起源，这表明该基因从真菌水平转移到跳虫。CaCel在pH 3.5时表现出最佳活性，在0-10°C下保留其80%的活性，并在70°C下保持4小时的半衰期。基于CaCel与真菌同源物的结构比较，我们推断出CaCel异常特性的结构基础。在50°C的酸性条件下，CaCel能有效消化绿藻（孔石莼），这表明它可用于从海藻生产生物燃料。
