PDBsum entry 1rzc

Lyase(oxo-acid)

PDB id: 1rzc

Contents

Protein chain

258 a.a. *

Ligands

OXY

Metals

_CU ×2

Waters ×216

* Residue conservation analysis

PDB id:

1rzc

Name:

Lyase(oxo-acid)

Title:

X-ray analysis of metal substituted human carbonic anhydrase ii derivatives

Structure:

Carbonic anhydrase ii. Chain: a. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606

Resolution:

1.90Å R-factor: 0.150

Authors:

K.Hakansson,A.Wehnert,A.Liljas

Key ref:

K.Håkansson et al. (1994). X-ray analysis of metal-substituted human carbonic anhydrase II derivatives. Acta Crystallogr D Biol Crystallogr, 50, 93. PubMed id: 15299481 DOI: 10.1107/S0907444993008790

Date:

25-May-93 Release date: 31-Oct-93

Protein chain

P00918  (CAH2_HUMAN) -  Carbonic anhydrase 2 from Homo sapiens

Seq: 260 a.a.

Struc: 258 a.a.

Enzyme reactions

• Enzyme class 2: E.C.4.2.1.1 - carbonic anhydrase.
• Reaction: hydrogencarbonate + H⁺ = CO2 + H2O
• Cofactor: Zn(2+)
• Enzyme class 3: E.C.4.2.1.69 - cyanamide hydratase.
• Reaction: urea = cyanamide + H2O

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1107/S0907444993008790

Acta Crystallogr D Biol Crystallogr 50:93 (1994)

PubMed id: 15299481

X-ray analysis of metal-substituted human carbonic anhydrase II derivatives.

K.Håkansson, A.Wehnert, A.Liljas.

ABSTRACT

Metal-substituted crystals of human carbonic anhydrase II belonging to space group P2(1) with cell dimensions a = 42.7, b = 41.7, c = 73.0 A and beta = 104.6 degrees were analyzed crystallographically. The resolution limit ranged from 1.82 to 1.92 A with high completeness (86.2-90.7%). Cobalt(II)-substituted carbonic anhydrase has a tetrahedral coordination around the metal both at pH 6 and pH 7.8, similar to the native zinc enzyme. In contrast, the catalytically inactive copper(II), nickel(II) and manganese(II) derivatives showed increased coordination number around the metal ion. Whereas the copper is best described as penta-coordinated, the nickel and manganese are best described as hexa-coordinated. The results are briefly compared with spectroscopic observations and our current view on carbonic anhydrase catalysis.

Selected figure(s)

Figure 1.
Fig. 1. The active-site structure of native human carbonic anhydrase II. The conformation of the peptide chain is the same in the native enzyme and all the metal-substituted derivatives described in this paper, but the solvent structure differs among the different substitutions. Waters 263 and 338 are sometimes referred to as the 'zinc water' and 'deep water', respectively. The structure was plotted using the coordinates of HD, ansson, Carlsson, Svensson & Liljas (1992).

Figure 3.
Fig. 3. The active site of cobalt(II)-substituted carbonic anhydrase at pit 6.0. Difference electron maps were calculated after refinement of native coordinates without waters 263, 338 and 339. Positive (continuous lines) and negative (broken lines) IFol - IFcI contours were drawn at +3e. The occupancy of the sulfate was refined to 0.6.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (1994, 50, 93-0) copyright 1994.

Figures were selected by an automated process.