PDBsum entry 1xfb

Lyase

PDB id: 1xfb

Contents

Protein chain

(+ 6 more) 342 a.a. *

* Residue conservation analysis

PDB id:

1xfb

Name:

Lyase

Title:

Human brain fructose 1,6-(bis)phosphate aldolase (c isozyme)

Structure:

AldolasE C. Chain: a, b, c, d, e, f, g, h, i, j, k, l. Synonym: fructose 1,6-(bis)phosphate aldolase. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Dodecamer (from PQS)

Resolution:

3.00Å R-factor: 0.255 R-free: 0.261

Authors:

T.L.Arakaki,J.A.Pezza,M.A.Cronin,C.E.Hopkins,D.B.Zimmer,D.R.Tolan, K.N.Allen

Key ref:

T.L.Arakaki et al. (2004). Structure of human brain fructose 1,6-(bis)phosphate aldolase: linking isozyme structure with function. Protein Sci, 13, 3077-3084. PubMed id: 15537755 DOI: 10.1110/ps.04915904

Date:

14-Sep-04 Release date: 08-Feb-05

Protein chains

P09972  (ALDOC_HUMAN) -  Fructose-bisphosphate aldolase C from Homo sapiens

Seq: 364 a.a.

Struc: 342 a.a.

Enzyme reactions

• Enzyme class: E.C.4.1.2.13 - fructose-bisphosphate aldolase.
• Reaction: beta-D-fructose 1,6-bisphosphate = D-glyceraldehyde 3-phosphate + dihydroxyacetone phosphate
• Cofactor: Zn(2+)

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

reference

DOI no: 10.1110/ps.04915904

Protein Sci 13:3077-3084 (2004)

PubMed id: 15537755

Structure of human brain fructose 1,6-(bis)phosphate aldolase: linking isozyme structure with function.

T.L.Arakaki, J.A.Pezza, M.A.Cronin, C.E.Hopkins, D.B.Zimmer, D.R.Tolan, K.N.Allen.

ABSTRACT

Fructose-1,6-(bis)phosphate aldolase is a ubiquitous enzyme that catalyzes the reversible aldol cleavage of fructose-1,6-(bis)phosphate and fructose 1-phosphate to dihydroxyacetone phosphate and either glyceral-dehyde-3-phosphate or glyceraldehyde, respectively. Vertebrate aldolases exist as three isozymes with different tissue distributions and kinetics: aldolase A (muscle and red blood cell), aldolase B (liver, kidney, and small intestine), and aldolase C (brain and neuronal tissue). The structures of human aldolases A and B are known and herein we report the first structure of the human aldolase C, solved by X-ray crystallography at 3.0 A resolution. Structural differences between the isozymes were expected to account for isozyme-specific activity. However, the structures of isozymes A, B, and C are the same in their overall fold and active site structure. The subtle changes observed in active site residues Arg42, Lys146, and Arg303 are insufficient to completely account for the tissue-specific isozymic differences. Consequently, the structural analysis has been extended to the isozyme-specific residues (ISRs), those residues conserved among paralogs. A complete analysis of the ISRs in the context of this structure demonstrates that in several cases an amino acid residue that is conserved among aldolase C orthologs prevents an interaction that occurs in paralogs. In addition, the structure confirms the clustering of ISRs into discrete patches on the surface and reveals the existence in aldolase C of a patch of electronegative residues localized near the C terminus. Together, these structural changes highlight the differences required for the tissue and kinetic specificity among aldolase isozymes.

Selected figure(s)

Figure 2.
Figure 2. The active site of aldolase C (red) with residues depicted as ball-and-stick, overlaid with the active site residues of aldolase A (blue; PDB accession code 1ALD [PDB] ) and aldolase B (green; PDB accession code 1QO5 [PDB] ).

Figure 3.
Figure 3. Stereo view of the active site residues of the aldolase C structure. The residues are shown as ball-and-stick models. The 2Fo-Fc electron density map contoured at 1 is depicted as blue cages.

The above figures are reprinted by permission from the Protein Society: Protein Sci (2004, 13, 3077-3084) copyright 2004.

Figures were selected by an automated process.