Arabidopsis Homologues to the LRAT a Possible Substrate for New Plant-Based Anti-Cancer Drug Development

Introduction

The H-Box/NC proteins were subsequently suggested to belong to a larger group of proteins, termed the NIpC/P60 superfamily. The NIpC/P60 superfamily was divided into four families according to their amino acid sequence similarities and motifs. The P60-like family, the ACMB/LytN-like divergent family, the lecithin retinal acyl transferase-like (LRAT-like) family and the YaeF/poxvirus G6R type family (Anantharaman & Aravind, 2003). The NIpC/P60 proteins are predicted to have a thiol-protease fold. This is made up of a β-strand region containing a conserved histidine, an orientating polar residue (part of a conserved GD [glucine-aspartic acid] motif) and a α-helix domain containing a conserved cysteine. Some members of the NIpC/P60 superfamily proteins (including the LRAT-like ones) exhibit circular permutation. In the thiol-protease fold area, variable sized inserts are often seen in the region between the strand containing the histidine and the strand bearing the orienting polar residue (Anantharaman & Aravind, 2003).