Structural Basis for Beta-Lactam Resistance of MRSA Uncovered

[Guest guest]

Hi,

since Becki is still in the club I'll play the backup here and post

some interesting scientific articles from the last week.

The first one gives some hope for those, who are struggling with

MRSA. Although I don't think MRSA is such a big problem for pwcf as

it is for the hospitals in general it's good to know that researchers

take care of the problem.

Peace

Torsten

Structural Basis for Beta-Lactam Resistance of MRSA Uncovered

NEW YORK (Reuters Health) Oct 21 - Canadian researchers have

determined

the structure of a protein that is largely responsible for the

beta-lactam resistance of methicillin-resistant Staphylococcus aureus

(MRSA).

S. aureus is known to produce penicillin-binding proteins (PBPs) that

play a key role in cell wall synthesis. Beta-lactam antibiotics

destroy

bacteria by binding to the PBPs and inhibiting cell wall synthesis.

However, with increasing antibiotic use, strains such as MRSA have

developed that are largely immune to the effects of beta-lactams.

A few years ago, researchers discovered that MRSA produced a PBP

variant

not seen in beta-lactam-sensitive bacteria. This variant, known as

PBP2a, was able to promote cell wall synthesis at beta-lactam

concentrations that would have inhibited other PBPs. Although the

apparent reason for MRSA resistance was now known, the structure of

PBP2a was not.

In the October 21st online issue of Nature Structural Biology, Dr.

Lim and Dr. C. J. Strynadka, from the University of

British Columbia in Vancouver, describe the crystal structure of

PBP2a.

The structure reveals how PBP2a promotes cell wall synthesis

unhindered

by beta-lactams, the researchers note. Knowledge of PBP2a's structure

may be useful in identifying newly developed beta-lactam antibiotics

that are effective against MRSA, they add.

Nat Struct Biol 2002;October 21st online issue.