PDBsum entry 1cau

Seed storage protein

PDB id: 1cau

Contents

Protein chains

181 a.a. *

184 a.a. *

* Residue conservation analysis

PDB id:

1cau

Name:

Seed storage protein

Title:

Determination of three crystal structures of canavalin by molecular replacement

Structure:

Canavalin. Chain: a. Engineered: yes. Canavalin. Chain: b. Engineered: yes

Source:

Canavalia ensiformis. Jack bean. Organism_taxid: 3823. Organism_taxid: 3823

Biol. unit:

Hexamer (from PQS)

Resolution:

2.30Å R-factor: 0.192

Authors:

T-P.Ko,J.D.Ng,J.Day,A.Greenwood,A.Mcpherson

Key ref:

T.P.Ko et al. (1993). Determination of three crystal structures of canavalin by molecular replacement. Acta Crystallogr D Biol Crystallogr, 49, 478-489. PubMed id: 15299507 DOI: 10.1107/S0907444993004056

Date:

08-Jul-93 Release date: 31-Oct-93

Protein chain

P50477  (CANA_CANEN) -  Canavalin from Canavalia ensiformis

Seq: 445 a.a.

Struc: 181 a.a.

Protein chain

P50477  (CANA_CANEN) -  Canavalin from Canavalia ensiformis

Seq: 445 a.a.

Struc: 184 a.a.

Enzyme reactions

• Enzyme class: Chains A, B: E.C.?

DOI no: 10.1107/S0907444993004056

Acta Crystallogr D Biol Crystallogr 49:478-489 (1993)

PubMed id: 15299507

Determination of three crystal structures of canavalin by molecular replacement.

T.P.Ko, J.D.Ng, J.Day, A.Greenwood, A.McPherson.

ABSTRACT

Canavalin, the major reserve protein of the jack bean, was obtained in four different crystal forms. From the structure determined by multiple isomorphous replacement in a hexagonal unit cell, the structures of three other crystals were determined by molecular replacement. In two cases, the rhombohedral and cubic crystals, placement was facilitated by coincidence of threefold molecular symmetry with crystallographic operators. In the orthorhombic crystal the canavalin trimer was the asymmetric unit. The rhombohedral, orthorhombic and cubic crystal structures were subsequently refined using a combination of several approaches with resulting R factors of 0.194, 0.185 and 0.211 at resolutions of 2.6, 2.6 and 2.3 A, respectively. Variation in the conformation of the molecule from crystal to crystal was small with an r.m.s. deviation in Calpha positions of 0.89 A. Packing is quite different among crystal forms but lattice interactions appear to play little role in the conformation of the molecule. Greatest variations in mean position are for those residues that also exhibit the greatest thermal motion. Crystal contacts in all crystals are mediated almost exclusively by hydrophilic side chains, and three to six intermolecular salt bridges per protein subunit are present in each case.

Selected figure(s)

Figure 3.
Fig. 3. A schematic drawing of the canavalin subunit. The polypeptide termini are labeled as N,, C~, ~ and C. The triangle indicates the location of the riad axis around which three monomers are arranged.

Figure 7.
Fig. 7. A Ramachandran pot showing most ¢,~b anges to be within allowed regions according t Morris et al. (1992). Symbols: (A) R3, non-glycine residues; (A) R3, glycines; (11) C222~, non-glycine residues; (r-q) C222~, glycines; (0) P2~3, non-glycine resiues; (O) P2~3, glycines.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (1993, 49, 478-489) copyright 1993.

Figures were selected by an automated process.