ISDA

Deposition Date 2001-05-09

Release Date 2001-10-03

Last Version Date 2023-09-20

Entry Detail

PDB ID:

1IM0

Keywords:

HYDROLASE, MEMBRANE PROTEIN

Title:

OUTER MEMBRANE PHOSPHOLIPASE A FROM ESCHERICHIA COLI N156A ACTIVE SITE MUTANT PH 8.3

Biological Source:

Source Organism:

Escherichia coli (Taxon ID: 562)

Host Organism:

Escherichia coli

Method Details:

Experimental Method:

X-RAY DIFFRACTION

Resolution:

2.98 Å

R-Value Free:

0.26

R-Value Work:

0.22

Space Group:

P 31 2 1

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Macromolecular Entities

Structures with similar UniProt ID

Protein Blast

Polymer Type:polypeptide(L)
Molecule:OUTER MEMBRANE PHSOPHOLIPASE A
Gene (Uniprot):pldA
Mutagens:N156A
Chain IDs:A
Chain Length:275
Number of Molecules:1
Biological Source:Escherichia coli

UniProt ID:P0A921 Pfam ID:PF02253

Ligand Molecules

BOG

MPD

Primary Citation

Structural investigations of the active-site mutant Asn156Ala of outer membrane phospholipase A: function of the Asn-His interaction in the catalytic triad.

Snijder, H.J, Van Eerde, J.H, Kingma, R.L, Kalk, K.H, Dekker, N, Egmond, M.R, Dijkstra, B.W, Snijder, H.J, Ubarretxena-Belandia, I, Blaauw, M, Kalk, K.H, Verheij, H.M, Egmond, M.R, Dekker, N, Dijkstra, B.W, Blaauw, M, Dekker, N, Verheij, H.M, Kalk, K.H, Dijkstra, B.W.Show

Protein Sci. 10 1962 1969 (2001)

PMID: 11567087 DOI: 10.1110/ps.17701

Abstact

Outer membrane phospholipase A (OMPLA) from Escherichia coli is an integral-membrane enzyme with a unique His-Ser-Asn catalytic triad. In serine proteases and serine esterases usually an Asp occurs in the catalytic triad; its role has been the subject of much debate. Here the role of the uncharged asparagine in the active site of OMPLA is investigated by structural characterization of the Asn156Ala mutant. Asparagine 156 is not involved in maintaining the overall active-site configuration and does not contribute significantly to the thermal stability of OMPLA. The active-site histidine retains an active conformation in the mutant notwithstanding the loss of the hydrogen bond to the asparagine side chain. Instead, stabilization of the correct tautomeric form of the histidine can account for the observed decrease in activity of the Asn156Ala mutant.

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