UNIGE document Scientific Article
previous document  unige:81822  next document
add to browser collection
Title

Structural modeling of the human erythrocyte bisphosphoglycerate mutase

Authors
Craescu, Constantin T.
Garel, Marie-Claude
Rosa, R.
Published in Biochimie. 1992, vol. 74, no. 6, p. 519-526
Abstract Using the crystallographic structure of yeast monophosphoglycerate mutase (MPGM) as a framework we constructed a three-dimensional model of the homologous human erythrocyte bisphosphoglycerate mutase (BPGM). The modeling procedure consisted of substituting 117 amino acid residues and positioning 19 C-terminal residues (unresolved in the X-ray structure) by empirical methods, followed by energy minimization. Among several differences in the active site region the most significant appears to be the replacement of Ser11 in MPGM by Gly in BPGM. The C-terminal segment, which contains mainly basic amino acids, lines the cavity of the active site. The seven amino acid residues, which have been shown to be essential for the three catalytic functions of the human BPGM, interact with the amino acids in the protein core, near the active site. In addition, a cluster of several positively charged residues, particularly arginines, has been identified at the entrance of the active site; this cluster may serve as a secondary binding site for polyanionic substrates or cofactors, as required by a two-binding-site model of the catalytic activities. This model is in agreement with recent studies of an inactive BPGM variant substituent at an Arg position situated in this positively charged cluster. The position of Cys20 in the model constructed suggests that this residue is responsible for inactivation of the enzyme by sulfhydryl reagents. Subunit interfaces have also been constructed for BPGM by analogy with MPGM and suggest that, in addition to the known dimerization of BPGM, tetramerization may occur under certain conditions.
Keywords Bisphosphoglycerate mutaseHomology modelingIntersubunit contacts
Identifiers
PMID: 1387804
Full text
Article (Published version) (875 Kb) - document accessible for UNIGE members only Limited access to UNIGE
Structures
Citation
(ISO format)
CRAESCU, Constantin T. et al. Structural modeling of the human erythrocyte bisphosphoglycerate mutase. In: Biochimie, 1992, vol. 74, n° 6, p. 519-526. https://archive-ouverte.unige.ch/unige:81822

106 hits

0 download

Update

Deposited on : 2016-03-10

Export document
Format :
Citation style :