Polypeptide ligation occurs during post-translational modification of concanavalin A

Nature. 1985 Jan;313(5997):64-7. doi: 10.1038/313064a0.

Abstract

Lectins are proteins with multivalent carbohydrate-binding sites, which confer the ability to agglutinate. The seeds of legumes are particularly rich in lectins, for example, concanavalin A (Con A) comprises up to 15% of the protein in the cotyledons of jack bean (Canavalia ensiformis) seeds. The amino acid sequences of Con A and several other legume lectins have been partially or fully determined, and comparison of these sequences from different species reveals a circular homology (Fig. 1A); rearrangements within the genome have been suggested to explain this. We report here that the circular homology displayed by Con A is due to a post-translational transposition and ligation within the initial polypeptide. This type of modification has not been reported previously for eukaryotes, although it has been suggested to occur in bacteriophage lambda.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Concanavalin A / genetics
  • Concanavalin A / metabolism*
  • Molecular Weight
  • Protein Precursors / genetics
  • Protein Processing, Post-Translational*

Substances

  • Protein Precursors
  • Concanavalin A

Associated data

  • GENBANK/X01632