GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:7736571

From GONUTS
Jump to: navigation, search
Citation

Navaratnam, N, Bhattacharya, S, Fujino, T, Patel, D, Jarmuz, AL and Scott, J (1995) Evolutionary origins of apoB mRNA editing: catalysis by a cytidine deaminase that has acquired a novel RNA-binding motif at its active site. Cell 81:187-95

Abstract

The site-specific C to U editing of apolipoprotein B100 (apoB100) mRNA requires a 27 kDa protein (p27) with homology to cytidine deaminase. Here, we show that p27 is a zinc-containing deaminase, which operates catalytically like the E. coli enzyme that acts on monomeric substrate. In contrast with the bacterial enzyme that does not bind RNA, p27 interacts with its polymeric apoB mRNA substrate at AU sequences adjacent to the editing site. This interaction is necessary for editing. RNA binding is mediated through amino acid residues involved in zinc coordination, in proton shuttling, and in forming the alpha beta alpha structure that encompasses the active site. However, certain mutations that inactivate the enzyme do not affect RNA binding. Thus, RNA binding does not require a catalytically active site. The acquisition of polymeric substrate binding provides a route for the evolution of this editing enzyme from one that acts on monomeric substrates.

Links

PubMed

Keywords

Amino Acid Sequence; Animals; Apolipoprotein B-100; Apolipoproteins B/genetics; Base Sequence; Binding Sites; Catalysis; Cytidine Deaminase/genetics; Cytidine Deaminase/metabolism; DNA Mutational Analysis; Humans; Metalloproteins/genetics; Metalloproteins/metabolism; Models, Molecular; Molecular Sequence Data; Phylogeny; Protein Binding; RNA Editing; RNA-Binding Proteins/genetics; RNA-Binding Proteins/metabolism; Rats; Sequence Deletion; Sequence Homology, Amino Acid; Structure-Activity Relationship; Zinc/metabolism

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

HUMAN:ABEC1

enables

GO:0004126: cytidine deaminase activity

ECO:0000304: author statement supported by traceable reference used in manual assertion

F

Seeded From UniProt

complete

HUMAN:ABEC1

enables

GO:0008270: zinc ion binding

ECO:0000304: author statement supported by traceable reference used in manual assertion

F

Seeded From UniProt

complete

HUMAN:ABEC1

involved_in

GO:0006396: RNA processing

ECO:0000304: author statement supported by traceable reference used in manual assertion

P

Seeded From UniProt

complete

HUMAN:ABEC1

enables

GO:0003723: RNA binding

ECO:0000304: author statement supported by traceable reference used in manual assertion

F

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.