Alteration of the co-substrate selectivity of deacetoxycephalosporin C synthase: The role of arginine-258Alteration of the co-substrate selectivity of deacetoxycephalosporin C synthase: The role of arginine-258

Structural highlights

1hjg is a 1 chain structure with sequence from Streptomyces clavuligerus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.5Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CEFE_STRCL Catalyzes the step from penicillin N to deacetoxy-cephalosporin C.

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

Deacetoxycephalosporin C synthase is an iron(II) 2-oxoglutaratedependent oxygenase that catalyzes the oxidative ring-expansion of penicillin N to deacetoxycephalosporin C. The wild-type enzyme is only able to efficiently utilize 2-oxoglutarate and 2-oxoadipate as a 2-oxoacid co-substrate. Mutation of arginine 258, the side chain of which forms an electrostatic interaction with the 5-carboxylate of the 2-oxoglutarate co-substrate, to a glutamine residue reduced activity to about 5% of the wild-type enzyme with 2-oxoglutarate. However, other aliphatic 2-oxoacids, which were not co-substrates for the wild-type enzyme, were utilized by the R258Q mutant. These 2-oxoacids "rescued" catalytic activity to the level observed for the wild-type enzyme as judged by penicillin N and G conversion. These co-substrates underwent oxidative decarboxylation as observed for 2-oxoglutarate in the normal reaction with the wild-type enzyme. Crystal structures of the iron(II)- 2-oxo-3-methylbutanoate (1.5 A), and iron(II)-2-oxo-4-methylpentanoate (1.6 A) enzyme complexes were obtained, which reveal the molecular basis for this "chemical co-substrate rescue" and help to rationalize the co-substrate selectivity of 2-oxoglutaratedependent oxygenases.

Alteration of the co-substrate selectivity of deacetoxycephalosporin C synthase. The role of arginine 258.,Lee HJ, Lloyd MD, Clifton IJ, Harlos K, Dubus A, Baldwin JE, Frere JM, Schofield CJ J Biol Chem. 2001 May 25;276(21):18290-5. Epub 2001 Feb 21. PMID:11279000[1]

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

References

  1. Lee HJ, Lloyd MD, Clifton IJ, Harlos K, Dubus A, Baldwin JE, Frere JM, Schofield CJ. Alteration of the co-substrate selectivity of deacetoxycephalosporin C synthase. The role of arginine 258. J Biol Chem. 2001 May 25;276(21):18290-5. Epub 2001 Feb 21. PMID:11279000 doi:http://dx.doi.org/10.1074/jbc.M100085200

1hjg, resolution 1.50Å

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