Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Imperfect DNA mirror repeats in the gag gene of HIV-1 (HXB2) identify key functional domains and coincide with protein structural elements in each of the mature proteins | Virology Journal BioMed Central Research Imperfect DNA mirror repeats in the gag gene of HIV-1 HXB2 identify key functional domains and coincide with protein structural elements in each of the mature proteins Dorothy M Lang Address School of Contemporary Sciences University of Abertay-Dundee Bell Street Dundee DD1 1HG Scotland UK Email Dorothy M Lang - dml_mail@ Open Access Published 26 October 2007 Received 28 September 2007 Accepted 26 October 2007 Virology Journal 2007 4 113 doi 1743-422X-4-113 This article is available from http content 4 1 1 13 2007 Lang licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background A DNA mirror repeat is a sequence segment delimited on the basis of its containing a center of symmetry on a single strand . 5 -GCATGGTACG-3 . It is most frequently described in association with a functionally significant site in a genomic sequence and its occurrence is regarded as noteworthy if not unusual. However imperfect mirror repeats IMRs having 50 symmetry are common in the protein coding DNA of monomeric proteins and their distribution has been found to coincide with protein structural elements - helices p sheets and turns. In this study the distribution of IMRs is evaluated in a polyprotein - to determine whether IMRs may be related to the position or order of protein cleavage or other hierarchal aspects of protein function. The gag gene of HIV-I GenBank K03455 was selected for the study because its protein motifs and structural components are well documented. Results There is a highly specific relationship between IMRs and structural and functional aspects of the Gag polyprotein. The five longest IMRs in the polyprotein translate a key functional segment