Human endogenous retrovirus family HERV-K(HML-5): status, evolution, and reconstruction of an ancient betaretrovirus in the human genome.
The human genome harbors numerous distinct families of so-called human endogenous retroviruses (HERV) which are remnants of exogenous retroviruses that entered the germ line millions of years ago. We describe here the hitherto little-characterized betaretrovirus HERV-K(HML-5) family (named HERVK22 in Repbase) in greater detail. Out of 139 proviruses, only a few loci represent full-length proviruses, and many lack gag protease and/or env gene regions. We generated a consensus sequence from multiple alignment of 62 HML-5 loci that displays open reading frames for the four major retroviral proteins. Four HML-5 long terminal repeat (LTR) subfamilies were identified that are associated with monophyletic proviral bodies, implying different evolution of HML-5 LTRs and genes. Sequence analysis indicated that the proviruses formed approximately 55 million years ago. Accordingly, HML-5 proviral sequences were detected in Old World and New World primates but not in prosimians. No recent activity is associated with this HERV family. We also conclude that the HML-5 consensus sequence primer binding site is identical to methionine tRNA. Therefore, the family should be designated HERV-M. Our study provides important insights into the structure and evolution of the oldest betaretrovirus in the primate genome known to date.
Department of Human Genetics, Building 60, University of Saarland, Medical Faculty, 66421 Homburg, Germany.
Laurence
L
Lavie
Patrik
P
Medstrand
Werner
W
Schempp
Eckart
E
Meese
Jens
J
Mayer
D000818:Animals; D001483:Base Sequence; D016384:Consensus Sequence; D020077:Endogenous Retroviruses / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D015894:Genome, Human; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011533:Proviruses / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020079:Terminal Repeat Sequences / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
D014764:Viral Proteins