TY - JOUR
T1 - Effects of a buried cysteine-to-serine mutation on yeast triosephosphate isomerase structure and stability
AU - Hernández-Santoyo, Alejandra
AU - Domínguez-Ramírez, Lenin
AU - Reyes-López, César A.
AU - González-Mondragón, Edith
AU - Hernández-Arana, Andrés
AU - Rodríguez-Romero, Adela
PY - 2012/8
Y1 - 2012/8
N2 - All the members of the triosephosphate isomerase (TIM) family possess a cystein residue (Cys126) located near the catalytically essential Glu165. The evolutionarily conserved Cys126, however, does not seem to play a significant role in the catalytic activity. On the other hand, substitution of this residue by other amino acid residues destabilizes the dimeric enzyme, especially when Cys is replaced by Ser. In trying to assess the origin of this destabilization we have determined the crystal structure of Saccharomyces cerevisiae TIM (ScTIM) at 1.86 Å resolution in the presence of PGA, which is only bound to one subunit. Comparisons of the wild type and mutant structures reveal that a change in the orientation of the Ser hydroxyl group, with respect to the Cys sulfhydryl group, leads to penetration of water molecules and apparent destabilization of residues 132-138. The latter results were confirmed by means of Molecular Dynamics, which showed that this region, in the mutated enzyme, collapses at about 70 ns.
AB - All the members of the triosephosphate isomerase (TIM) family possess a cystein residue (Cys126) located near the catalytically essential Glu165. The evolutionarily conserved Cys126, however, does not seem to play a significant role in the catalytic activity. On the other hand, substitution of this residue by other amino acid residues destabilizes the dimeric enzyme, especially when Cys is replaced by Ser. In trying to assess the origin of this destabilization we have determined the crystal structure of Saccharomyces cerevisiae TIM (ScTIM) at 1.86 Å resolution in the presence of PGA, which is only bound to one subunit. Comparisons of the wild type and mutant structures reveal that a change in the orientation of the Ser hydroxyl group, with respect to the Cys sulfhydryl group, leads to penetration of water molecules and apparent destabilization of residues 132-138. The latter results were confirmed by means of Molecular Dynamics, which showed that this region, in the mutated enzyme, collapses at about 70 ns.
KW - Crystal structure
KW - Molecular dynamics
KW - Saccharomyces cerevisiae
KW - Stability
KW - Triosephosphate isomerase
UR - http://www.scopus.com/inward/record.url?scp=84865010673&partnerID=8YFLogxK
U2 - 10.3390/ijms130810010
DO - 10.3390/ijms130810010
M3 - Artículo
SN - 1661-6596
VL - 13
SP - 10010
EP - 10021
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 8
ER -