PDF(Pubmed)
Abstract：
Copper homeostasis is a fundamental process in organisms, characterised by unique pathways that have evolved to meet specific needs while preserving core resistance mechanisms. While these systems are well-documented in model bacteria, information on copper resistance in species adapted to cold environments is scarce. This study investigates the potential genes related to copper homeostasis in the genome of Bizionia argentinensis (JUB59-T), a psychrotolerant bacterium isolated from Antarctic seawater. We identified several genes encoding proteins analogous to those crucial for copper homeostasis, including three sequences of copper-transport P1B-type ATPases. One of these, referred to as BaCopA1, was chosen for cloning and expression in Saccharomyces cerevisiae. BaCopA1 was successfully integrated into yeast membranes and subsequently extracted with detergent. The purified BaCopA1 demonstrated the ability to catalyse ATP hydrolysis at low temperatures. Structural models of various BaCopA1 conformations were generated and compared with mesophilic and thermophilic homologous structures. The significant conservation of critical residues and structural similarity among these proteins suggest a shared reaction mechanism for copper transport. This study is the first to report a psychrotolerant P1B-ATPase that has been expressed and purified in a functional form.
摘要：
铜稳态是生物体内的一个基本过程，以独特的途径为特征，这些途径已经进化以满足特定需求，同时保留核心抗性机制。虽然这些系统在模型细菌中有很好的记录，有关适应寒冷环境的物种中铜抗性的信息很少。本研究调查了阿根廷白菊（JUB59-T）基因组中与铜稳态相关的潜在基因，一种从南极海水中分离出的精神耐受细菌。我们确定了几个编码类似于对铜稳态至关重要的蛋白质的基因，包括三个铜转运P1B型ATP酶序列。其中一个,被称为BaCopA1，被选择用于在酿酒酵母中克隆和表达。BaCopA1成功整合到酵母膜中，随后用洗涤剂提取。纯化的BaCopA1证明了在低温下催化ATP水解的能力。生成了各种BaCopA1构象的结构模型，并将其与嗜中和嗜热同源结构进行了比较。关键残基的显着保守性和这些蛋白质之间的结构相似性表明了铜转运的共同反应机制。这项研究首次报道了一种精神耐受性P1B-ATPase，该酶已以功能形式表达和纯化。
