Structural and functional insights into peptidoglycan access for the lytic amidase LytA of Streptococcus pneumoniae.

ABSTRACT:

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The cytosolic N-acetylmuramoyl-l-alanine amidase LytA protein of Streptococcus pneumoniae, which is released by bacterial lysis, associates with the cell wall via its choline-binding motif. During exponential growth, LytA accesses its peptidoglycan substrate to cause lysis only when nascent peptidoglycan synthesis is stalled by nutrient starvation or β-lactam antibiotics. Here we present three-dimensional structures of LytA and establish the requirements for substrate binding and catalytic activity. The solution structure of the full-length LytA dimer reveals a peculiar fold, with the choline-binding domains forming a rigid V-shaped scaffold and the relatively more flexible amidase domains attached in a trans position. The 1.05-Å crystal structure of the amidase domain r

SUBMITTER: Mellroth P 

PROVIDER: S-EPMC3950521 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature