tailieunhanh - Báo cáo y học: "The AID/APOBEC family of nucleic acid mutators"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: The AID/APOBEC family of nucleic acid mutators. | Protein family review The AID APOBEC family of nucleic acid mutators Silvestro G Conticello Address Core Research Laboratory - Istituto Toscano Tumori Florence Via Cosimo il Vecchio 2 50139 Firenze Italy. Email Published 17 June 2008 Genome Biology 2008 9 229 doi gb-2008-9-6-229 The electronic version of this article is the complete one and can be found online at http 2008 9 6 229 2008 BioMed Central Ltd Summary The AID APOBECs a group of cytidine deaminases represent a somewhat unusual protein family that can insert mutations in DNA and RNA as a result of their ability to deaminate cytidine to uridine. The ancestral AID APOBECs originated from a branch of the zinc-dependent deaminase superfamily at the beginning of the vertebrate radiation. Other members of the family have arisen in mammals and present a history of complex gene duplications and positive selection. All AID APOBECs have a characteristic zinc-coordination motif which forms the core of the catalytic site. The crystal structure of human APOBEC2 shows remarkable similarities to that of the bacterial tRNA-editing enzyme TadA which suggests a conserved mechanism by which polynucleotides are recognized and deaminated. The AID APOBECs seem to have diverse roles. AID and the APOBEC3s are DNA mutators acting in antigen-driven antibody diversification processes and in an innate defense system against retroviruses respectively. APOBEC1 edits the mRNA for apolipoprotein B a protein involved in lipid transport. A detailed understanding of the biological roles of the family is still some way off however and the functions of some members of the family are completely unknown. Given their ability to mutate DNA a role for the AID APOBECs in the onset of cancer has been proposed. Gene organization and evolutionary history The AID APOBEC proteins are found in vertebrates and share the ability to insert mutations in DNA and RNA by deaminating cytidine to uridine. The