Boreskov

PP‐67ADAPTATION OF THE PYROCOCCUS SPECIES TO DIFFERENT ENVIRONMENTALCONDITIONS: ANALYSIS OF THE EVOLUTION AT THE PROTEOMIC ANDSTRUCTURAL LEVELSAfonnikov D.A. 1,2 , Gunbin K.V. 1 , Medvedev K.E. 1 , Suslov V.V. 1 , Kolchanov N.A. 11 Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia2 Novosibirsk State University, Novosibirsk, RussiaDeep sea hydrothermal vents represent extreme habitats with high temperature andpressure. It is assumed that these conditions were common for early life at the Earth [1].Thus, studying the evolution of the microorganisms from deep sea hydrothermal ventbiotopes can shed light on the life origin. From the other hand, such analysis can provideimportant information about adaptation of microorganisms to extreme environments in thecourse of evolution.We investigated the evolution of three archaeal species of the Pyrococcus genus fromhydrothermal vents: deep sea P. abyssi and P. horikoshii and shallow‐water P. furiosus [2]. Itwas demonstrated that the function of proteins that have been subject to positive Darwinianselection is closely related to abiotic and biotic conditions to which archaea managed tobecome adapted. It was shown that the pressure is important environmental factor in thecourse of evolution. Nevertheless, adaptation to pressure does not appear to be the solefactor ensuring adaptation to environment. For example, at the stage of the divergence of P.horikoshii and P. abyssi, an essential evolutionary role may be assigned to changes in thetrophic chain, namely, acquisition of a consumer status at a high (P. horikoshii) or low level(P. abyssi).We present results of the comparative analysis of the molecular dynamics simulation ofNip7 proteins from the P. abyssi and P. furiosus species. These proteins are involved inribosomal biogenesis, participate in 27S pre‐rRNA processing and 60S ribosomal subunitformation [2]. We investigated changes of the polypeptide chain conformation and solventaccessibility at different pressures (0.1 ‐ 300 MPa) and temperatures (300 and 373 K).Obtained data suggested that the RNA‐binding domain of the P. abyssi Nip7 protein ismore resistant to the effects of high pressure. Our data also suggests that the interactions ofthese proteins with solvent are different and could be important for adaptation to highpressureconditions at the protein structure level.119