Halovibrin, secreted from the light organ symbiont Vibrio fischeri, is a member of a new class of ADP-ribosyltransferases.
The purification, cloning, and deduced amino acid sequence of an ADP-ribosyltransferase secreted from the marine bacterium Vibrio fischeri (V. fischeri ADP-r) is described. This enzyme was purified from culture supernatant, and partial amino acid sequence obtained from the purified protein was used to design a degenerate oligonucleotide probe that was used to clone a cross-hybridizing DNA fragment from V. fischeri genomic DNA. Recombinant Escherichia coli clones harboring this fragment possessed ADP-ribosyltransferase activity. The DNA fragment was sequenced, and deletion analysis localized the ADP-ribosyltransferase activity to one of the three possible open reading frames in the fragment; the deduced amino acid sequence from this open reading frame matched the amino acid sequence obtained from the purified protein. V. fischeri ADP-r has no significant homology (DNA or amino acid) with other known ADP-ribosyltransferases. This enzyme appears to require neither proteolytic cleavage nor a reducing agent for enzymatic activity. The cloned gene is expressed but not secreted in E. coli; however, it is secreted from a heterologous marine Vibrio species. We have named this enzyme halovibrin.
Howard Hughes Medical Institute, Stanford University School of Medicine, California 94305, USA.
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D002772:Cholera Toxin / Q000235:genetics; D003001:Cloning, Molecular; D004229:Dithiothreitol; D005798:Genes, Bacterial / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010430:Pentosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D017421:Sequence Analysis; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D013439:Sulfhydryl Reagents; D013559:Symbiosis; D014733:Vibrio / Q000201:enzymology* / Q000235:genetics
D001426:Bacterial Proteins; D013439:Sulfhydryl Reagents; D002772:Cholera Toxin; D010430:Pentosyltransferases; C097620:hvn protein, Vibrio fischeri; D011065:Poly(ADP-ribose) Polymerases; D004229:Dithiothreitol