A possible role of the second calcium ion in interfacial binding: Atomic and medium resolution crystal structures of the quadruple mutant of phospholipase A2A possible role of the second calcium ion in interfacial binding: Atomic and medium resolution crystal structures of the quadruple mutant of phospholipase A2

Structural highlights

2bd1 is a 2 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.9Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PA21B_BOVIN PA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides.

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The crystal structures of the monoclinic and trigonal forms of the quadruple mutant K53,56,120,121M of recombinant bovine pancreatic phospholipase A2 (PLA2) have been solved and refined at 1.9 and 1.1 A resolution, respectively. Interestingly, the monoclinic form reveals the presence of the second calcium ion. Furthermore, the surface-loop residues are ordered and the conformation of residues 62-66 is similar to that observed in other structures containing the second calcium ion. On the other hand, in the trigonal form the surface loop is disordered and the second calcium is absent. Docking studies suggest that the second calcium and residues Lys62 and Asp66 from the surface loop could be involved in the interaction with the polar head group of the membrane phospholipid. It is hypothesized that the two structures of the quadruple mutant, monoclinic and trigonal, represent the conformations of PLA2 at the lipid interface and in solution, respectively. A docked structure with a phospholipid molecule and with a transition-state analogue bound, one at the active site coordinating to the catalytic calcium and the other at the second calcium site, but both at the i-face, is presented.

Suggestive evidence for the involvement of the second calcium and surface loop in interfacial binding: monoclinic and trigonal crystal structures of a quadruple mutant of phospholipase A2.,Sekar K, Yogavel M, Kanaujia SP, Sharma A, Velmurugan D, Poi MJ, Dauter Z, Tsai MD Acta Crystallogr D Biol Crystallogr. 2006 Jul;62(Pt 7):717-24. Epub 2006, Jun 20. PMID:16790927[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Sekar K, Yogavel M, Kanaujia SP, Sharma A, Velmurugan D, Poi MJ, Dauter Z, Tsai MD. Suggestive evidence for the involvement of the second calcium and surface loop in interfacial binding: monoclinic and trigonal crystal structures of a quadruple mutant of phospholipase A2. Acta Crystallogr D Biol Crystallogr. 2006 Jul;62(Pt 7):717-24. Epub 2006, Jun 20. PMID:16790927 doi:10.1107/S0907444906014855

2bd1, resolution 1.90Å

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