Thomloudi Eirini-Evangelia, Skagia Aggeliki, Venieraki Anastasia, Katinakis Panagiotis, Dimou Maria
Laboratory of General and Agricultural Microbiology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece.
World J Microbiol Biotechnol. 2017 Feb;33(2):28. doi: 10.1007/s11274-016-2201-6. Epub 2017 Jan 5.
The nitrogen fixing Sinorhizobium meliloti possesses two genes, ppiA and ppiB, encoding two cyclophilin isoforms which belong to the superfamily of peptidyl prolyl cis/trans isomerases (PPIase, EC: 5.2.1.8). Here, we functionally characterize the two proteins and we demonstrate that both recombinant cyclophilins are able to isomerise the Suc-AAPF-pNA synthetic peptide but neither of them displays chaperone function in the citrate synthase thermal aggregation assay. Furthermore, we observe that the expression of both enzymes increases the viability of E. coli BL21 in the presence of abiotic stress conditions such as increased heat and salt concentration. Our results support and strengthen previous high-throughput studies implicating S. meliloti cyclophilins in various stress conditions.
固氮苜蓿中华根瘤菌拥有两个基因，ppiA和ppiB，它们编码两种亲环蛋白异构体，这两种异构体属于肽基脯氨酰顺/反异构酶（PPIase，EC：5.2.1.8）超家族。在此，我们对这两种蛋白质进行了功能表征，并证明两种重组亲环蛋白都能够使Suc-AAPF-pNA合成肽异构化，但在柠檬酸合酶热聚集试验中它们都不具有伴侣功能。此外，我们观察到在诸如热和盐浓度增加等非生物胁迫条件下，这两种酶的表达都能提高大肠杆菌BL21的活力。我们的结果支持并强化了先前的高通量研究，这些研究表明苜蓿中华根瘤菌亲环蛋白与各种胁迫条件有关。
