1HTZ

CRYSTAL STRUCTURE OF TEM52 BETA-LACTAMASE

Summary for 1HTZ

• Entry DOI: 10.2210/pdb1htz/pdb
• Related: 1TEM
• Descriptor: BETA-LACTAMASE MUTANT TEM52 (2 entities in total)
• Functional Keywords: mutant form of beta-lactamase, hydrolase
• Biological source: Klebsiella pneumoniae
• Total number of polymer chains: 6
• Total formula weight: 173651.99

Authors

Stevens, R.C.,Orencia, M.C. (deposition date: 2001-01-03, release date: 2001-03-21, Last modification date: 2024-10-30)

Primary citation

Orencia, M.C.,Yoon, J.S.,Ness, J.E.,Stemmer, W.P.,Stevens, R.C.
Predicting the emergence of antibiotic resistance by directed evolution and structural analysis.
Nat.Struct.Biol., 8:238-242, 2001

PubMed Abstract: Directed evolution can be a powerful tool to predict antibiotic resistance. Resistance involves the accumulation of mutations beneficial to the pathogen while maintaining residue interactions and core packing that are critical for preserving function. The constraint of maintaining stability, while increasing activity, drastically reduces the number of possible mutational combination pathways. To test this theory, TEM-1 beta-lactamase was evolved using a hypermutator E. coli-based directed evolution technique with cefotaxime selection. The selected mutants were compared to two previous directed evolution studies and a database of clinical isolates. In all cases, evolution resulted in the generation of the E104K/M182T/G238S combination of mutations ( approximately 500-fold increased resistance), which is equivalent to clinical isolate TEM-52. The structure of TEM-52 was determined to 2.4 A. G238S widens access to the active site by 2.8 A whereas E104K stabilizes the reorganized topology. The M182T mutation is located 17 A from the active site and appears to be a global suppressor mutation that acts to stabilize the new enzyme structure. Our results demonstrate that directed evolution coupled with structural analysis can be used to predict future mutations that lead to increased antibiotic resistance.

PubMed: 11224569
DOI: 10.1038/84981

Experimental method

X-RAY DIFFRACTION (2.4 Å)