In Silico Structural and Functional Annotations of Hypothetical Protein All4871 as a 1-Acyl-sn-Glycerol-3-Phosphate Acyltransferase from Nostoc sp. PCC 7120

Abstract

In this study, the in silico structural and functional characterization of a hypothetical protein All4871 from Nostoc sp. PCC 7120 was performed. The 287 amino acid residue protein sequence revealed considerable homology with 1-acyl-sn-glycerol-3-phosphate acyltransferase (AGPAT) from different organisms. Multiple sequence alignment of All4871 with the AGPAT isomers showed the presence of conserved motifs (motif I-IV) crucial for acyltransferase activity. The All4871 protein depicted the characteristic topology of membrane-bound AGPATs. Both N- and C-terminus of the All4871 protein face the inner side of the membrane. The predicted tertiary structure of All4871 has an N-terminal helix and αβ catalytic core, which are characteristic features of AGPATs. Amongst the CASTp predicted binding pockets, pocket 1 acts as a groove-spanning active site crucial for acyltransferase catalysis, lysophosphatidic acid (LPA), and acyl coA (MCL) binding site. Docking studies further supported pocket 1 as the binding site for both LPA and MCL, which act as substrates for acyltransferase catalysis. So, the overall analyses have pointed toward the possibility that the hypothetical protein All4871 from Nostoc sp. PCC7120 may act as a 1-acyl-sn-glycerol-3-phosphate acyltransferase.