Bizionia argentinensis copper chaperones

NOELIA INÉS BURGARDT; GUSTAVO APESTEGUIA; F. LUIS GONZÁLEZ FLECHA

San Javier

Congreso; XLI Reunión Anual de la Sociedad Argentina de Biofísica; 2012

Sociedad Argentina de Biofísica

Cellular copper homeostasis depends of two key proteins, the CPx-type heavy metal ATPases, which transport copper across cell membranes, and the copper chaperones, which mediate intracellular copper transport.1 Among the copper chaperone proteins there is a group known as CopZ, whose function is to transfer copper to CPx-type heavy metal ATPases. The three-dimensional structure of CopZ proteins from several organisms have been determined.2 The general fold is highly conserved and consists of a twisted four-stranded antiparallel β-sheet and two α-helices which are located on the same side of the β-sheet. The metal binding motif (MXCXXC) is found both in copper binding proteins, such as in proteins that bind another metals. The genome of Bizionia argentinensis (JUB59-T), a psycrophilic bacterium from the Antarctica sea surface, was recently reported.3 The are four open reading frames in B. argentinensis genome with homology to CopZ. Two putative proteins (BaCopZ-33 and BaCopZ-57), which should encoded for small proteins (13.1 and 15.5 kDa, respectively), were selected by our group. Here, we report the cloning, expression and preliminary characterization of BaCopZ-33 and BaCopZ-57. The study of these psychrophilic proteins and its interaction with copper would provide novel data on the mechanism of copper binding at low temperatures and would allow a comparison with the structures and mechanisms of analogous CopZ proteins from mesophilic organisms. 1. Arnesano F., et al, Genome Res., 12:255-271, 2002. 2. Boal A.K., et al, Chem. Rev., 109:4760-4779, 2009. 3. Bercovich A., et al, Int. J Syst. Evol. Microbiol., 58:2363-2367, 2008.