engleski

The structure of ADP-ribosyltransferase SCO3734 from bacterium Streptomyces coelicolor

ADP-ribosyltransferases (ARTs) catalyze the transfer of ADP-ribose from nicotinamide adenine dinucleotide (NAD) to diverse target molecules: proteins, antibiotics, nucleic acids and small chemical groups. The ART superfamily is characterized by extreme divergence at the sequence level often making it difficult to identify new members trough sequence analysis alone. We structurally characterised potential ART from Streptomyces coelicolor - SCO3734. High-resolution crystal structure (1.8 Å) revealed strongly conserved core fold characteristic for the members of the ART family. This core consists of a split β-sheet formed by two distinct units of three strands each, with most strands alternately interleaved between the two units. SCO3734 3D structure was compared with protein database using DALI web server. Generated results showed greatest similarity to protein CC0527 from bacterium Caulobacter crescentus (%id = 29, RMSD = 2.1, Z score = 12.2) and KptA homologue from archaeon Aeropyrum pernix (%id = 16, RMSD = 2.6, Z score = 9.0). In order to investigate SCO3734 function and potential substrates, we used the PROBIS web server. The results showed two potential binding sites, one for NAD+ cofactor and the other for molecules similar to carboxyatractyloside – highly toxic diterpene glycoside that inhibits the ADP/ATP translocase. Based on the structural similarity between carboxyatractyloside and glycoside antibiotics we assume that the latter could be substrates of SCO3734.

ADP-ribosylation ; ADP-ribosyltransferase ; Streptomyces coelicolor

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