title: Functional analysis of the two cyclophilin isoforms of Sinorhizobium meliloti.
abstract: 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.
authors.affiliation: Laboratory of General and Agricultural Microbiology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece.
authors.forename: Eirini-Evangelia
authors.initials: EE
authors.lastname: Thomloudi
authors.affiliation: Laboratory of General and Agricultural Microbiology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece.
authors.forename: Aggeliki
authors.initials: A
authors.lastname: Skagia
authors.affiliation: Laboratory of General and Agricultural Microbiology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Venieraki
authors.affiliation: Laboratory of General and Agricultural Microbiology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Katinakis
authors.affiliation: Laboratory of General and Agricultural Microbiology, Faculty of Crop Science, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece. mdimou@aua.gr.
authors.forename: Maria
authors.initials: M
authors.lastname: Dimou
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D021983:Cyclophilins / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D006358:Hot Temperature; D050296:Microbial Viability; D009842:Oligopeptides / Q000737:chemistry; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D054712:Salinity; D016962:Sinorhizobium meliloti / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D001426:Bacterial Proteins; D009842:Oligopeptides; D020033:Protein Isoforms; C043307:succinyl-alanyl-alanyl-prolyl-phenylalanine-4-nitroanilide; D021983:Cyclophilins
keywords: Abiotic stress; Cyclophilin; Peptidyl-prolyl cis/trans isomerase; Sinorhizobium meliloti