JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Stabb, E. V.
Right arrow Articles by Ruby, E. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Stabb, E. V.
Right arrow Articles by Ruby, E. G.

Journal of Bacteriology, January 2001, p. 309-317, Vol. 183, No. 1
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.1.309-317.2001

Vibrio fischeri Genes hvnA and hvnB Encode Secreted NAD+-Glycohydrolases

Eric V. Stabb,1,* Karl A. Reich,2,dagger and Edward G. Ruby1

Pacific Biomedical Research Center, University of Hawaii, Honolulu, Hawaii 96813,1 and Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 943052

Received 22 June 2000/Accepted 27 September 2000

HvnA and HvnB are proteins secreted by Vibrio fischeri ES114, an extracellular light organ symbiont of the squid Euprymna scolopes, that catalyze the transfer of ADP-ribose from NAD+ to polyarginine. Based on this activity, HvnA and HvnB were presumptively designated mono-ADP-ribosyltransferases (ARTases), and it was hypothesized that they mediate bacterium-host signaling. We have cloned hvnA and hvnB from strain ES114. hvnA appears to be expressed as part of a four-gene operon, whereas hvnB is monocistronic. The predicted HvnA and HvnB amino acid sequences are 46% identical to one another and share 44% and 34% identity, respectively, with an open reading frame present in the Pseudomonas aeruginosa genome. Four lines of evidence indicate that HvnA and HvnB mediate polyarginine ADP-ribosylation not by ARTase activity, but indirectly through an NAD+-glycohydrolase (NADase) activity that releases free, reactive, ADP-ribose: (i) like other NADases, and in contrast to the ARTase cholera toxin, HvnA and HvnB catalyzed ribosylation of not only polyarginine but also polylysine and polyhistidine, and ribosylation was inhibited by hydroxylamine; (ii) HvnA and HvnB cleaved 1,N6-etheno-NAD+ and NAD+; (iii) incubation of HvnA and HvnB with [32P]NAD+ resulted in the production of ADP-ribose; and (iv) purified HvnA displayed an NADase Vmax of 400 mol min-1 mol-1, which is within the range reported for other NADases and 102- to 104-fold higher than the minor NADase activity reported in bacterial ARTase toxins. Construction and analysis of an hvnA hvnB mutant revealed no other NADase activity in culture supernatants of V. fischeri, and this mutant initiated the light organ symbiosis and triggered regression of the light organ ciliated epithelium in a manner similar to that for the wild type.

* Corresponding author. Mailing address: Pacific Biomedical Research Center, University of Hawaii, 41 Ahui St., Honolulu, HI 96813. Phone: (808) 539-7311. Fax: (808) 599-4817. E-mail: stabb{at}hawaii.edu.

dagger Present address: Abbott Laboratories, Abbott Park, IL 60064.

Journal of Bacteriology, January 2001, p. 309-317, Vol. 183, No. 1
0021-9193/01/$04.00+0   DOI: 10.1128/JB.183.1.309-317.2001


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2001 by the American Society for Microbiology. All rights reserved.