PDBsum entry: 1k30

Transferase

PDB id: 1k30

Contents

Protein chain

363 a.a. *

Waters ×473

* Residue conservation analysis

PDB id:

1k30

Name:

Transferase

Title:

Crystal structure analysis of squash (cucurbita moschata) glycerol-3-phosphate (1)-acyltransferase

Structure:

Glycerol-3-phosphate acyltransferase. Chain: a. Synonym: glycerol-3-phosphate (1)-acyltransferase, gpat. Engineered: yes

Source:

Cucurbita moschata. Crookneck pumpkin. Organism_taxid: 3662. Gene: plsb. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.90Å R-factor: 0.188 R-free: 0.224

Authors:

A.P.Turnbull,J.B.Rafferty,S.E.Sedelnikova,A.R.Slabas, T.P.Schierer,J.T.Kroon,J.W.Simon,T.Fawcett,I.Nishida, N.Murata,D.W.Rice

Key ref:

A.P.Turnbull et al. (2001). Analysis of the structure, substrate specificity, and mechanism of squash glycerol-3-phosphate (1)-acyltransferase. Structure, 9, 347-353. PubMed id: 11377195 DOI: 10.1016/S0969-2126(01)00595-0

Date:

01-Oct-01 Release date: 31-Oct-01

Protein chain

P10349  (PLSB_CUCMO) -  Glycerol-3-phosphate acyltransferase, chloroplastic

Seq: 396 a.a.

Struc: 363 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.2.3.1.15 - Glycerol-3-phosphate O-acyltransferase.
• Reaction: Acyl-CoA + sn-glycerol 3-phosphate = CoA + 1-acyl-sn-glycerol 3-phosphate

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

 Gene Ontology (GO) functional annotation 

• Cellular component: plastid (3 terms)
• Biological process: metabolic process (2 terms)
• Biochemical function: transferase activity (3 terms)

reference

DOI no: 10.1016/S0969-2126(01)00595-0

Structure 9:347-353 (2001)

PubMed id: 11377195

Analysis of the structure, substrate specificity, and mechanism of squash glycerol-3-phosphate (1)-acyltransferase.

A.P.Turnbull, J.B.Rafferty, S.E.Sedelnikova, A.R.Slabas, T.P.Schierer, J.T.Kroon, J.W.Simon, T.Fawcett, I.Nishida, N.Murata, D.W.Rice.

ABSTRACT

BACKGROUND: Glycerol-3-phosphate (1)-acyltransferase(G3PAT) catalyzes the incorporation of an acyl group from either acyl-acyl carrier proteins (acylACPs) or acyl-CoAs into the sn-1 position of glycerol 3-phosphate to yield 1-acylglycerol-3-phosphate. G3PATs can either be selective, preferentially using the unsaturated fatty acid, oleate (C18:1), as the acyl donor, or nonselective, using either oleate or the saturated fatty acid, palmitate (C16:0), at comparable rates. The differential substrate specificity for saturated versus unsaturated fatty acids seen within this enzyme family has been implicated in the sensitivity of plants to chilling temperatures. RESULTS: The three-dimensional structure of recombinant G3PAT from squash chloroplast has been determined to 1.9 A resolution by X-ray crystallography using the technique of multiple isomorphous replacement and provides the first representative structure of an enzyme of this class. CONCLUSIONS: The tertiary structure of G3PAT comprises two domains, the larger of which, domain II, features an extensive cleft lined by hydrophobic residues and contains at one end a cluster of positively charged residues flanked by a H(X)(4)D motif, which is conserved amongst many glycerolipid acyltransferases. We predict that these hydrophobic and positively charged residues represent the binding sites for the fatty acyl substrate and the phosphate moiety of the glycerol 3-phosphate, respectively, and that the H(X)(4)D motif is a critical component of the enzyme's catalytic machinery.

Selected figure(s)

Figure 2.
Figure 2. Stereo Diagrams of Squash G3PAT(a) A schematic representation with the strands and helices labeled and colored red and green, respectively. The figure was prepared using MOLSCRIPT [26].(b) Ca trace with every tenth residue dotted and every twentieth residue numbered. The pattern of sequence conservation across members of the G3PAT family is also illustrated. Residues that are fully conserved across all five representative G3PAT sequences are colored green, residues that are fully conserved in chilling-resistant (arabidopsis, pea, and spinach) plants but differ in chilling-sensitive plants (squash and cucumber) are highlighted in red, and the remainder are highlighted in blue. The modeled positions of the glycerol 3-phosphate and fatty acyl substrate moieties are shown in atom colors (carbon, white; oxygen, red; and phosphate, pink) and cyan, respectively. The figure was prepared using MIDAS PLUS [27 and 28]

The above figure is reprinted by permission from Cell Press: Structure (2001, 9, 347-353) copyright 2001.

Figure was selected by an automated process.