Retrotransposon Gag Like 6 is a protein encoded by the RTL6 gene in humans. RTL6 is a member of the Mart family of genes, which are related to Sushi-like retrotransposons and were derived from fish and amphibians. The RTL6 protein is localized to the nucleus and has a predicted leucine zipper motif that is known to bind nucleic acids in similar proteins, such as LDOC1. Gene Locus The gene is on Chromosome 22 (human) at 22q13.31 on the minus strand from 44492570 to 44498125 nt on the GRCh38.p7 assembly of the human genome. Aliases for the gene include LDOC1L, MAR6, MART6, and SIRH3. RTL6 is made up of 2 exons and is encoded by 5556 base pairs of DNA . Origin RTL6 is a retrotransposon GAG related gene. It is one of eleven MART (Mammalian Retrotransposon Derived) genes in humans related to Sushi-like retrotransposons with long terminal repeats from fish and amphibians. Between 170 and 310 MYA, MART genes lost their ability to retrotranspose and concomitantly gained new, beneficial function for its host organism. mRNA RTL6 has an alternate start of transcription 140 base pairs upstream of the normal transcribed region. The lengths of the primary mRNA and that with the upstream start of transcription are 5355 and 5495 base pairs respectively. Protein Primary information The primary amino acid sequence for RTL6 is made up of 239 residues. There are no known alternative splice variants of the protein. The molecular weight of the protein is 26.2 kDa and the isoelectric point is 11.58. RTL6 is a proline and arginine rich protein. Domains and motifs RTL6 contains a predicted leucine zipper motif known to participate in nucleic acid binding in other proteins. RTL6 also contains a domain of unknown function from amino acid residues 98-177 . RTL6 is one of a number of genes belonging to the DUF4939 (domain of unknown function) superfamily. Secondary structure The secondary structure of RTL6 is made up of largely alpha helices. One region of RTL6 is also predicted to participate in a coiled-coil structure from amino acid residues 29–63. Post-translational modifications There are also two predicted phosphorylation sites for Protein Kinase C with high confidence scores at amino acid residues 6 and 45. There is also a predicted ubiquitination site with medium-confidence at amino acid residue 8. Cellular sublocation RTL6 is expected to be localized to the nucleus and cytosol based on the presence of