GIN-2

The Gypsy-like-Integrase Type 2 (GIN-2) (Bao et al. 2010; Marin 2010) is an intron-exon host integrase (INT) gene of 1.2-3.4 kb, exclusively found in the genomes of vertebrates. The name of GIN-2 logically derives from the previous description of a counterpart of GIN-2 called GIN-1. These two genes are not true paralogs but host genes evolved from the pool of GINGER1 elements, which in turn are related to LTR retroelement INTs. The GIN-2 product shows the typical INT core but it apparently lacks the GPY/F module typically observed in the phyologenetic relatives of GIN2 (such as the GIN1 protein, the LTR retroelement INTs and the GINGER1 transposons). For simplicity´s sake the figure below shows the genomic structure without introns.

There are two complementary classifications for the GINGER1 elements. Based on sequence these elements can be classified as DDE TRs and INTs. Based on INT-like structural potential similarities, the INT coded by GINGER1 elements are members of the Retroviral Integrase Superfamily (Nowotny 2009) of nucleic acid-processing enzymes involved in; a) selfish evolution; b) replication and repair of DNA; c) recombination and gene fusion; d) RNA-mediated gene silencing; and e) oncogenesis.