1IBV
STRUCTURE OF THE D53,54N MUTANT OF HISTIDINE DECARBOXYLASE BOUND WITH HISTIDINE METHYL ESTER AT-170 C
Summary for 1IBV
| Entry DOI | 10.2210/pdb1ibv/pdb |
| Related | 1HQ6 1IBT 1IBU 1IBW 1PYA |
| Descriptor | HISTIDINE DECARBOXYLASE BETA CHAIN, Histidine decarboxylase alpha chain, HISTIDINE-METHYL-ESTER, ... (4 entities in total) |
| Functional Keywords | substrate-induced activation, active form, site-directed mutant, pyruvoyl, carboxy-lyase, lyase |
| Biological source | Lactobacillus sp. 30A More |
| Total number of polymer chains | 6 |
| Total formula weight | 102913.28 |
| Authors | Worley, S.,Schelp, E.,Monzingo, A.F.,Ernst, S.,Robertus, J.D. (deposition date: 2001-03-29, release date: 2002-03-13, Last modification date: 2024-02-14) |
| Primary citation | Worley, S.,Schelp, E.,Monzingo, A.F.,Ernst, S.,Robertus, J.D. Structure and cooperativity of a T-state mutant of histidine decarboxylase from Lactobacillus 30a. Proteins, 46:321-329, 2002 Cited by PubMed Abstract: Histidine decarboxylase (HDC) from Lactobacillus 30a converts histidine to histamine, a process that enables the bacteria to maintain the optimum pH range for cell growth. HDC is regulated by pH; it is active at low pH and inactive at neutral to alkaline pH. The X-ray structure of HDC at pH 8 revealed that a helix was disordered, resulting in the disruption of the substrate-binding site. The HDC trimer has also been shown to exhibit cooperative kinetics at neutral pH, that is, histidine can trigger a T-state to R-state transition. The D53,54N mutant of HDC has an elevated Km, even at low pH, indicating that the enzyme assumes the low activity T-state. We have solved the structures of the D53,54N mutant at low pH, with and without the substrate analog histidine methyl ester (HME) bound. Structural analysis shows that the apo-D53,54N mutant is in the inactive or T-state and that binding of the substrate analog induces the enzyme to adopt the active or R-state. A mechanism for the cooperative transition is proposed. PubMed: 11835507DOI: 10.1002/prot.10042 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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