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.
Lavie
Laurence
L
Department of Human Genetics, Building 60, University of Saarland, Medical Faculty, 66421 Homburg, Germany.
Medstrand
Patrik
P
Schempp
Werner
W
Meese
Eckart
E
Mayer
Jens
J
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