Phosphotransferase KptA/Tpt1 (IPR002745)

Short name: Ptrans_KptA/Tpt1

Overlapping homologous superfamilies


Family relationships


The final step of tRNA splicing in Saccharomyces cerevisiae (Baker's yeast) requires 2'-phosphotransferase (Tpt1) to transfer the 2'-phosphate from ligated tRNA to NAD, producing mature tRNA and ADP ribose-1' '-2' '-cyclic phosphate. Yeast and Mus musculus (Mouse) Tpt1 protein and bacterial KptA protein can catalyze the conversion of the generated intermediate to both product and the original substrate, these enzymes likely use the same reaction mechanism. Step 1 of this reaction is strikingly similar to the ADP-ribosylation of proteins catalyzed by a number of bacterial toxins.

KptA, a functional Tpt1 protein homologue from Escherichia coli is strikingly similar to yeast Tpt1 in its kinetic parameters, although E. coli is not known to have a 2'-phosphorylated RNA substrate [PMID: 9915792,PMID: 11705403].

GO terms

Biological Process

GO:0006388 tRNA splicing, via endonucleolytic cleavage and ligation

Molecular Function

GO:0016772 transferase activity, transferring phosphorus-containing groups

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.