title: An insight into the sequential, structural and phylogenetic properties of banana 1-aminocyclopropane-1-carboxylate synthase 1 and study of its interaction with pyridoxal-5'-phosphate and aminoethoxyvinylglycine.
abstract: In banana, ethylene production for ripening is accompanied by a dramatic increase in 1-aminocyclopropane-1-carboxylate (ACC) content, transcript level of Musa acuminata ACC synthase 1 (MA-ACS1) and the enzymatic activity of ACC synthase 1 at the onset of the climacteric period. MA-ACS1 catalyses the conversion of S-adenosyl-L-methionine (SAM) to ACC, the key regulatory step in ethylene biosynthesis. Multiple sequence alignments of 1-aminocyclopropane-1-carboxylate synthase (ACS) amino acid sequences based on database searches have indicated that MA-ACS1 is a highly conserved protein across the plant kingdom. This report describes an in silico analysis to provide the first important insightful information about the sequential, structural and phylogenetic characteristics of MA-ACS1. The three-dimensional structure of MA-ACS1, constructed based on homology modelling, in combination with the available data enabled a comparative mechanistic analysis of MA-ACS1 to explain the catalytic roles of the conserved and non-conserved active site residues. We have further demonstrated that, as in apple and tomato, banana- ACS1 (MA-ACS1) forms a homodimer and a complex with cofactor pyridoxal-5'-phosphate (PLP) and inhibitor aminoethoxyvinylglycine (AVG). We have also predicted that the residues from the PLP-binding pocket, essential for ligand binding, are mostly conserved across the MA-ACS1 structure and the competitive inhibitor AVG binds at a location adjacent to PLP.
authors.affiliation: Department of Botany, Bose Institute, 93/1, APC Road, Kolkata 700 009.
authors.forename: Swarup Roy
authors.initials: SR
authors.lastname: Choudhury
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Singh
authors.forename: Sujit
authors.initials: S
authors.lastname: Roy
authors.forename: Dibyendu N
authors.initials: DN
authors.lastname: Sengupta
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005030:Ethylenes / Q000378:metabolism; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D008190:Lyases / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D028521:Musa / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D011732:Pyridoxal Phosphate / Q000737:chemistry / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D005030:Ethylenes; D010940:Plant Proteins; D011732:Pyridoxal Phosphate; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase; C088137:aminoethoxyvinylglycine; D005998:Glycine