Adaptation of aminoacyl-tRNA synthetase catalytic core to carrier protein aminoacylation.
Structure
; 21(4): 614-26, 2013 Apr 02.
Article
en En
| MEDLINE
| ID: mdl-23541895
ABSTRACT
Amino acid[carrier protein] ligases (aaCP ligases) are recently discovered enzymes that are highly similar to class II aminoacyl-tRNA synthetases (aaRSs). However, while aaRSs aminoacylate tRNA and supply building blocks for ribosomal translation, aaCP ligases transfer activated amino acids to the phosphopantetheine group of small carrier proteins. We have solved the crystal structure of an aaCP ligase complexed with the carrier protein (CP). The CP prosthetic group enters the active site from a different direction than tRNA in class II aaRS complexes through an idiosyncratic tunnel. CP binds to aaCP ligase in a fundamentally different manner compared to tRNA binding by structurally closely related aaRSs. Based on crystallographic analysis, an enzyme of altered CP specificity was designed, and the mechanism of amino acid transfer to the prosthetic group was proposed. The presented study reveals how a conserved class II aaRS catalytic core can adapt to another function through minor structural alterations.
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Bases de datos:
MEDLINE
Asunto principal:
Conformación Proteica
/
Proteínas Portadoras
/
Modelos Moleculares
/
Bradyrhizobium
/
Complejos Multiproteicos
/
Aminoacil-ARNt Sintetasas
/
Ligasas
Idioma:
En
Revista:
Structure
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
/
BIOTECNOLOGIA
Año:
2013
Tipo del documento:
Article
País de afiliación:
Croacia