  6.2.1.B5 | ATP + L-alanine + [acyl-carrier protein Atu2571] |
the carrier protein Atu2571 is cloned and overexpressed in Escherichia coli (UniProt: A9CHM9). The 4'-phosphopantetheinyl prosthetic group is attached to purified apo-carrier proteins. The enzyme is homologous to the catalytic domain of highly diverged, atypical seryl-tRNA synthetases found only in methanogenic archaea and are deprived of the tRNA-binding domain. In comparison to seryl-tRNA synthetases, the homolog displays different and relaxed amino acid specificity. The homolog lacks canonical tRNA aminoacylating activity and instead transfers activated amino acid to phosphopantetheine prosthetic group of putative carrier proteins, whose genes are identified in the genomic surroundings of the homolog. In the ATP-diphosphate exchange assay the enzyme prefers L-alanine over L-glycine or L-serine about 30-40fold, and activates L-Glu and L-Pro albeit more than three orders of magnitude less efficiently than L-alanine |
Agrobacterium tumefaciens |
AMP + diphosphate + L-alanyl-[acyl-carrier protein Atu2571] |
- |
? |
