1HZO

STRUCTURE OF CLASS A CEPHALOSPORINASE FROM PROTEUS VULGARIS K1

Summary for 1HZO

• Entry DOI: 10.2210/pdb1hzo/pdb
• Descriptor: BETA-LACTAMASE, 2-(N-MORPHOLINO)-ETHANESULFONIC ACID (3 entities in total)
• Functional Keywords: mixed alpha/beta, cephalosporinase, class a beta-lactamase, hydrolase
• Biological source: Proteus vulgaris
• Total number of polymer chains: 2
• Total formula weight: 59769.27

Authors

Nukaga, M.,Crichlow, G.V.,Kuzin, A.P.,Mayama, K.,Knox, J.R. (deposition date: 2001-01-25, release date: 2002-04-03, Last modification date: 2023-08-09)

Primary citation

Nukaga, M.,Mayama, K.,Crichlow, G.V.,Knox, J.R.
Structure of an extended-spectrum class A beta-lactamase from Proteus vulgaris K1.
J.Mol.Biol., 317:109-117, 2002

PubMed Abstract: The structure of a chromosomal extended-spectrum beta-lactamase (ESBL) having the ability to hydrolyze cephalosporins including cefuroxime and ceftazidime has been determined by X-ray crystallography to 1.75 A resolution. The species-specific class A beta-lactamase from Proteus vulgaris K1 was crystallized at pH 6.25 and its structure solved by molecular replacement. Refinement of the model resulted in crystallographic R and R(free) of 16.9 % and 19.3 %, respectively. The folding of the K1 enzyme is broadly similar to that of non-ESBL TEM-type beta-lactamases (2 A rmsd for C(alpha)) and differs by only 0.35 A for all atoms of six conserved residues in the catalytic site. Other residues promoting extended-spectrum activity in K1 include the side-chains of atypical residues Ser237 and Lys276. These side-chains are linked by two water molecules, one of which lies in the position normally filled by the guanidinium group of Arg244, present in most non-ESBL enzymes but absent from K1. The ammonium group of Lys276, ca 3.5 A from the virtual Arg244 guanidinium position, may interact with polar R2 substitutents on the dihydrothiazene ring of cephalosporins.

PubMed: 11916382
DOI: 10.1006/jmbi.2002.5420

Experimental method

X-RAY DIFFRACTION (1.75 Å)