Structural adaptation of enzymes to low temperatures

@article{citeulike:2288264, abstract = {A systematic comparative analysis of 21 psychrophilic enzymes belonging to different structural families from prokaryotic and eukaryotic organisms is reported. The sequences of these enzymes were multiply aligned to 427 homologous proteins from mesophiles and thermophiles. The net flux of amino acid exchanges from meso/thermophilic to psychrophilic enzymes was measured. To assign the observed preferred exchanges to different structural environments, such as secondary structure, solvent accessibility and subunit interfaces, homology modeling was utilized to predict the secondary structure and accessibility of amino acid residues for the psychrophilic enzymes for which no experimental three-dimensional structure is available. Our results show a clear tendency for the charged residues Arg and Glu to be replaced at exposed sites on {alpha}-helices by Lys and Ala, respectively, in the direction from `hot' to `cold' enzymes. Val is replaced by Ala at buried regions in {alpha}-helices. Compositional analysis of psychrophilic enzymes shows a significant increase in Ala and Asn and a decrease in Arg at exposed sites. Buried sites in {beta}-strands tend to be depleted of Val. Possible implications of the observed structural variations for protein stability and engineering are discussed. 10.1093/protein/14.3.141}, author = {Gianese, Giulio and Argos, Patrick and Pascarella, Stefano }, citeulike-article-id = {2288264}, doi = {10.1093/protein/14.3.141}, journal = {Protein Eng.}, keywords = {adaptation, enzyme, for-thuber, psychrophily, structure, thermal}, month = {March}, number = {3}, pages = {141--148}, posted-at = {2008-01-25 06:43:28}, priority = {2}, title = {Structural adaptation of enzymes to low temperatures}, url = {http://dx.doi.org/10.1093/protein/14.3.141}, volume = {14}, year = {2001} }

TY - JOUR ID - citeulike:2288264 L3 - citeulike-article-id:2288264 TI - Structural adaptation of enzymes to low temperatures JF - Protein Eng. VL - 14 IS - 3 SP - 141 EP - 148 N2 - A systematic comparative analysis of 21 psychrophilic enzymes belonging to different structural families from prokaryotic and eukaryotic organisms is reported. The sequences of these enzymes were multiply aligned to 427 homologous proteins from mesophiles and thermophiles. The net flux of amino acid exchanges from meso/thermophilic to psychrophilic enzymes was measured. To assign the observed preferred exchanges to different structural environments, such as secondary structure, solvent accessibility and subunit interfaces, homology modeling was utilized to predict the secondary structure and accessibility of amino acid residues for the psychrophilic enzymes for which no experimental three-dimensional structure is available. Our results show a clear tendency for the charged residues Arg and Glu to be replaced at exposed sites on {alpha}-helices by Lys and Ala, respectively, in the direction from `hot' to `cold' enzymes. Val is replaced by Ala at buried regions in {alpha}-helices. Compositional analysis of psychrophilic enzymes shows a significant increase in Ala and Asn and a decrease in Arg at exposed sites. Buried sites in {beta}-strands tend to be depleted of Val. Possible implications of the observed structural variations for protein stability and engineering are discussed. 10.1093/protein/14.3.141 KW - adaptation KW - enzyme KW - for-thuber KW - psychrophily KW - structure KW - thermal AU - Gianese, Giulio AU - Argos, Patrick AU - Pascarella, Stefano PY - 2001/03/01/ UR - http://dx.doi.org/10.1093/protein/14.3.141 ER -