Structural highlights
Function
[MALE_ECO57] Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides (By similarity).
Publication Abstract from PubMed
Activation-induced deoxycytidine deaminase (AID) initiates somatic hypermutation (SHM) and class-switch recombination (CSR) by deaminating C-->U during transcription of Ig-variable (V) and Ig-switch (S) region DNA, which is essential to produce high-affinity antibodies. Here we report the crystal structure of a soluble human AID variant at 2.8A resolution that favors targeting WRC motifs (W=A/T, R=A/G) in vitro, and executes Ig V SHM in Ramos B-cells. A specificity loop extending away from the active site to accommodate two purine bases next to C, differs significantly in sequence, length, and conformation from APOBEC proteins Apo3A and Apo3G, which strongly favor pyrimidines at -1 and -2 positions. Individual amino acid contributions to specificity and processivity were measured in relation to a proposed ssDNA binding cleft. This study provides a structural basis for residue contributions to DNA scanning properties unique to AID, and for disease mutations in human HIGM-2 syndrome.
Structural analysis of the activation-induced deoxycytidine deaminase required in immunoglobulin diversification.,Pham P, Afif SA, Shimoda M, Maeda K, Sakaguchi N, Pedersen LC, Goodman MF DNA Repair (Amst). 2016 Jul;43:48-56. doi: 10.1016/j.dnarep.2016.05.029. Epub, 2016 May 13. PMID:27258794[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Pham P, Afif SA, Shimoda M, Maeda K, Sakaguchi N, Pedersen LC, Goodman MF. Structural analysis of the activation-induced deoxycytidine deaminase required in immunoglobulin diversification. DNA Repair (Amst). 2016 Jul;43:48-56. doi: 10.1016/j.dnarep.2016.05.029. Epub, 2016 May 13. PMID:27258794 doi:http://dx.doi.org/10.1016/j.dnarep.2016.05.029
