PDBsum entry 1nns

Hydrolase

PDB id: 1nns

Contents

Protein chains

326 a.a. *

Ligands

ASP ×2

Waters ×329

* Residue conservation analysis

PDB id:

1nns

Name:

Hydrolase

Title:

L-asparaginase of e. Coli in c2 space group and 1.95 a resolution

Structure:

L-asparaginase ii. Chain: a, b. Synonym: l-asparagine amidohydrolase ii. Ec: 3.5.1.1

Source:

Escherichia coli. Organism_taxid: 562

Biol. unit:

Hexamer (from PDB file)

Resolution:

1.95Å R-factor: 0.132 R-free: 0.171

Authors:

M.Sanches,J.A.R.G.Barbosa,R.T.De Oliveira,J.A.A.Neto,I.Polikarpov

Key ref:

M.Sanches et al. (2003). Structural comparison of Escherichia coli L-asparaginase in two monoclinic space groups. Acta Crystallogr D Biol Crystallogr, 59, 416-422. PubMed id: 12595697 DOI: 10.1107/S0907444902021200

Date:

14-Jan-03 Release date: 11-Mar-03

Protein chains

P00805  (ASPG2_ECOLI) -  L-asparaginase 2 from Escherichia coli (strain K12)

Seq: 348 a.a.

Struc: 326 a.a.

Enzyme reactions

• Enzyme class: E.C.3.5.1.1 - asparaginase.
• Reaction: L-asparagine + H2O = L-aspartate + NH4⁺

L-asparagine + H2O = L-aspartate (Bound ligand (Het Group name = ASP) corresponds exactly) + NH4(+)

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

Added reference

DOI no: 10.1107/S0907444902021200

Acta Crystallogr D Biol Crystallogr 59:416-422 (2003)

PubMed id: 12595697

Structural comparison of Escherichia coli L-asparaginase in two monoclinic space groups.

M.Sanches, J.A.Barbosa, R.T.de Oliveira, J.Abrahão Neto, I.Polikarpov.

ABSTRACT

The functional L-asparaginase from Escherichia coli is a homotetramer with a molecular weight of about 142 kDa. The X-ray structure of the enzyme, crystallized in a new form (space group C2) and refined to 1.95 A resolution, is compared with that of the previously determined crystal form (space group P2(1)). The asymmetric unit of the new crystal form contains an L-asparaginase dimer instead of the tetramer found in the previous crystal form. It is found that crystal contacts practically do not affect the conformation of the protein. It is shown that subunit C of the tetrameric form is in a conformation which is systematically different from that of all other subunits in both crystal forms. Major conformational differences are confined to the lid loop (residues 14-27). In addition, the stability of this globular protein is analyzed in terms of the interactions between hydrophobic parts of the subunits.

Selected figure(s)

Figure 2.
Figure 2 A schematic representation of the E. coli L-asparaginase subunit produced using MOLSCRIPT (Kraulis, 1991[Kraulis, P. J. (1991). J. Appl. Cryst. 24, 946-950.]). Secondary structures marked N belong to the N-terminal domain and those marked C belong to the C-terminal domain. The 3[10]-helices N 1, N 3, N 6 and N 10 are shown in opaque green.

Figure 3.
Figure 3 A graphical representation of the L-asparaginase tetramer produced using MOLSCRIPT (Kraulis, 1991[Kraulis, P. J. (1991). J. Appl. Cryst. 24, 946-950.]). Intimate dimers are formed by subunits drawn in yellow/blue and green/pink.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2003, 59, 416-422) copyright 2003.

Figures were selected by an automated process.