Differences in the enzymatic efficiency of human and bony fish AID are mediated by a single residue in the C terminus modulating single‐stranded DNA binding

Activation‐induced cytidine deaminase (AID) mediates antibody diversification by deaminating deoxycytidines to deoxyuridine within immunoglobulin genes. However, it also generates genome‐wide DNA lesions, leading to transformation. Though the biochemical properties of AID have been described, its 3‐...

Full description

Saved in:
Bibliographic Details
Published in:The FASEB journal Vol. 26; no. 4; pp. 1517 - 1525
Main Authors: Dancyger, Alex M., King, Justin J., Quinlan, Matthew J., Fifield, Heather, Tucker, Stephanie, Saunders, Holly L., Berru, Maribel, Magor, Bradley G., Martin, Alberto, Larijani, Mani
Format: Journal Article
Language:English
Published: Bethesda, MD, USA Federation of American Societies for Experimental Biology 01-04-2012
Subjects:
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Activation‐induced cytidine deaminase (AID) mediates antibody diversification by deaminating deoxycytidines to deoxyuridine within immunoglobulin genes. However, it also generates genome‐wide DNA lesions, leading to transformation. Though the biochemical properties of AID have been described, its 3‐dimensional structure has not been determined. Hence, to investigate the relationship between the primary structure and biochemical characteristics of AID, we compared the properties of human and bony fish AID, since these are most divergent in amino acid sequence. We show that AIDs of various species have different catalytic rates that are thermosensitive and optimal at native physiological temperatures. Zebrafish AID is severalfold more catalytically robust than human AID, while catfish AID is least active. This disparity is mediated by a single amino acid difference in the C terminus. Using functional assays supported by models of AID core and surface structure, we show that this residue modulates activity by affecting ssDNA binding. Furthermore, the cold‐adapted catalytic rates of fish AID result from increased ssDNA binding affinity at lower temperatures. Our work suggests that AID may generate DNA damage with variable efficiencies in different organisms, identifies residues critical in regulating AID activity, and provides insights into the evolution of the APOBEC family of enzymes.—Dancyger, A. M., King, J. J., Quinlan, M. J., Fifield, H., Tucker, S., Saunders, H. L., Berru, M., Magor, B. G., Martin, A., Larijani, M. Differences in the enzymatic efficiency of human and bony fish AID are mediated by a single residue in the C terminus modulating single‐stranded DNA binding. FASEB J. 26, 1517‐1525 (2012). www.fasebj.org
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ObjectType-Article-1
ObjectType-Feature-2
ISSN:0892-6638
1530-6860
DOI:10.1096/fj.11-198135