Annotation inferences using phylogenetic trees
Characterization of a novel Zn²⁺-dependent intrinsic imipenemase from Pseudomonas aeruginosa.
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Purified PA5542 hydrolyses imipenem, with zinc dependence.
"Spectrophotometric analyses showed that PA5542 is a Zn(2+)-dependent imipenemase."
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Inactivation of PA5542 raises carbapenem susceptibility and its overexpression lowers carbapenem susceptibility in E. coli.
"Lack of PA5542 increases P. aeruginosa 59.20 susceptibility to carbapenems and its overexpression reduces E. coli susceptibility to these β-lactams."
A new type of Class C β-lactamases defined by PIB-1. A metal-dependent carbapenem-hydrolyzing β-lactamase, from Pseudomonas aeruginosa: Structural and functional analysis.
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Crystal structures place PIB-1 (PA5542) in the class C beta-lactamases.
"These crystal structures show that it belongs to the Class C β-lactamase group"
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PIB-1 degrades carbapenems but not cephalosporins, and metal ions stimulate activity through trimer formation rather than active-site binding.
"Functional analysis showed that PIB-1 is able to degrade carbapenems but not cephalosporins, the typical substrate of Class C β-lactamases, and that its catalytic activity increases in the presence of metal ions, especially zinc."