UC Berkeley

TLA1 (Truncated Light harvesting Antenna 1) protein belongs to a novel uncharacterized protein family. It was first identified in the green microalga, Chlamydomonas reinhardtii. The TLA1 like proteins are present in diverse groups of eukaryotes ranging from algae, higher plants, insects and mammals. Currently the protein domains present in the members of this unknown protein family lack a homology to any known well characterized functional domain. To date, the exact functional roles of TLAl-like proteins in organisms, when present, are unknown because of lack of existence of a well characterized functional domain. The aim of this study is to identify a functional domain in the TLA1 like proteins through application of computational-based bioinformatics tools. BLAST-P helped to identify two specific domains within the conserved regions of TLAl-like proteins. A PHYRE hit, 2095B (the chain B, crystal structure of the metal-free dimeric human MPN domain), aligned well with the first conserved domain of the TLA1 protein, both at the primary sequence and secondary structural level. A comparative model of the Chlamydomonas TLA1 protein was built using the 2095B protein sequence as a template. Key putative hydrophobic and catalytic amino acid residues were identified, that are also present in certain MPN domain- containing proteins. This study has shown that TLA1 like proteins have a plain MPN- domain. The MPN domain specific key amino acids that we have identified can be tested experimentally in the future to better define the functional role of TLA1 like proteins. © 2012 Academic Journals Inc.