1hcb is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The structure of HCAI-HCO3- complex has been refined with 10-1.6A X-ray diffraction data to an R-value of 17.7%. The structure reveals monodentate binding of the HCO3- anion at an apical tetrahedral position to the zinc ion. The binding mode and interactions of HCO3- in HCAI differ from that in HCAII. The activity linked H2O/OH- group in the free HCAI is replaced by the hydroxyl group of the bicarbonate anion. This result rules out the rearrangement of the bound HCO3- advocated earlier to explain the microscopic reversibility of the catalysed reaction. From the geometry of the H-bonds between Glu106-Thr199 pair and Glu117-His119 couple, the glutamic acids are expected to be ionized and accept H-bonds from their partners. The product-inhibiton by HCO3- anion is explained on the basis of proton localization on His119 in the Glu117-His119 couple. These results are consistent with the hypothesis that Glu117-His119 tunes the ionicity of the Zn2+ and the binding strength of HCO3- anion. A pi hydrogen bond is observed between a water and phenyl ring of the Tyr114 residue.
Enzyme-substrate interactions. Structure of human carbonic anhydrase I complexed with bicarbonate.,Kumar V, Kannan KK J Mol Biol. 1994 Aug 12;241(2):226-32. PMID:8057362[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Kumar V, Kannan KK. Enzyme-substrate interactions. Structure of human carbonic anhydrase I complexed with bicarbonate. J Mol Biol. 1994 Aug 12;241(2):226-32. PMID:8057362 doi:http://dx.doi.org/10.1006/jmbi.1994.1491
