Evidence that Blastocladiella emersonii zoospore maintenance factor is a sulfhydryl group-containing cyclic ribotide.

Published

Journal Article

Blastocladiella emersonii zoospore maintenance factor (ZMF), released into the medium during zoospore production, mediates a reversible developmental block to zoospore encystment (Gottschalk, W. K., and Sonneborn, D. R. (1981) Exp. Mycol. 5, 1-14 and (1982) Dev. Biol. 93, 165-180). Crude ZMF and purified ZMF display indistinguishable sensitivities/insensitivities to inactivations by several different chemical or enzymatic treatments. Such data have provided additional support for the conclusion (Gottschalk, W. K., and Sonneborn, D. R. (1985) J. Biol. Chem. 260, 6588-6591) that ZMF biological activity resides in a single molecular species. The inactivation analyses have provided substantial evidence that ZMF is a newly discovered SH-containing cyclic ribotide. At least one SH-containing side group and at least one free amino group linked to an imidazole, as well as a ribosyl moiety containing a cyclic 3',5'-phosphate, a 2'-free hydroxyl, and a 1'-linkage to the imidazole, appear to be essential structural requirements for ZMF-mediated encystment blockage. The proposed structure of biologically functional ZMF is similar to that of a key intermediate in the de novo pathway of purine nucleotide biosynthesis (5'-phosphoribosyl-5-aminoimidazole-4-N-succino-carboxamide), except that ZMF, and not 5'-phosphoribosyl-5-aminoimidazole-4-N-succinocarboxamide, contains a cyclic phosphate and at least one reduced SH group.

Full Text

Duke Authors

Cited Authors

  • Gottschalk, WK; Sonneborn, DR

Published Date

  • June 10, 1985

Published In

Volume / Issue

  • 260 / 11

Start / End Page

  • 6592 - 6599

PubMed ID

  • 3997839

Pubmed Central ID

  • 3997839

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng

Conference Location

  • United States