1MB9

BETA-LACTAM SYNTHETASE COMPLEXED WITH ATP

Summary for 1MB9

• Entry DOI: 10.2210/pdb1mb9/pdb
• Related: 1JGT 1MBZ 1MC1
• Descriptor: BETA-LACTAM SYNTHETASE, MAGNESIUM ION, PYROPHOSPHATE 2-, ... (6 entities in total)
• Functional Keywords: clavulanic acid, asparagine synthetase, beta-lactam synthetase, carboxyethyl arginine, deoxyguanidinoproclavaminic acid, hydrolase
• Biological source: Streptomyces clavuligerus
• Total number of polymer chains: 2
• Total formula weight: 110837.89

Authors

Miller, M.T.,Bachmann, B.O.,Townsend, C.A.,Rosenzweig, A.C. (deposition date: 2002-08-02, release date: 2002-10-23, Last modification date: 2024-02-14)

Primary citation

Miller, M.T.,Bachmann, B.O.,Townsend, C.A.,Rosenzweig, A.C.
The catalytic cycle of beta -lactam synthetase observed by x-ray crystallographic snapshots
Proc.Natl.Acad.Sci.USA, 99:14752-14757, 2002

PubMed Abstract: The catalytic cycle of the ATP/Mg(2+)-dependent enzyme beta-lactam synthetase (beta-LS) from Streptomyces clavuligerus has been observed through a series of x-ray crystallographic snapshots. Chemistry is initiated by the ordered binding of ATP/Mg(2+) and N(2)-(carboxyethyl)-l-arginine (CEA) to the apoenzyme. The apo and ATP/Mg(2+) structures described here, along with the previously described CEA.alpha,beta-methyleneadenosine 5'-triphosphate (CEA.AMP-CPP)/Mg(2+) structure, illuminate changes in active site geometry that favor adenylation. In addition, an acyladenylate intermediate has been trapped. The substrate analog N(2)-(carboxymethyl)-l-arginine (CMA) was adenylated by ATP in the crystal and represents a close structural analog of the previously proposed CEA-adenylate intermediate. Finally, the structure of the ternary product complex deoxyguanidinoproclavaminic acid (DGPC).AMP/PP(i)/Mg(2+) has been determined. The CMA-AMP/PP(i)/Mg(2+) and DGPC.AMP/PP(i)/Mg(2+) structures reveal interactions in the active site that facilitate beta-lactam formation. All of the ATP-bound structures differ from the previously described CEA.AMP-CPP/Mg(2+) structure in that two Mg(2+) ions are found in the active sites. These Mg(2+) ions play critical roles in both the adenylation and beta-lactamization reactions.

PubMed: 12409610
DOI: 10.1073/pnas.232361199

Experimental method

X-RAY DIFFRACTION (2.11 Å)