Genome-wide Identification and Characterization of the Pectin Methylesterase (PME) and Pectin Methylesterase Inhibitor (PMEI) Gene Family in the Banana A-genome (Musa acuminata) and B-genome (Musa balbisiana)

Pectin methylesterase (PME) is a ubiquitous cell-wall-associated enzyme that catalyzes the demethylesterification of homogalacturonan in the cell wall. The activity is regulated in part by pectin methylesterase inhibitor (PMEI), which can bind to the active site of PME. This mechanism may result in either rigidification or softening of the cell wall depending on the mechanism of demethylesterification. This research aims to characterize the structure and function of the PME and PMEI gene family in A (Musa acuminata) and B (Musa balbisiana) banana genomes. We annotated based on domain PME (PF019095) and PMEI (PF04043) using the PFAM database. We analyzed the size, weight, isoelectric point of the protein, signal peptide, transmembrane domain, subcellular localization of proteins, prediction cleavage motif and position, phylogenetic analysis and conserved residues. As a result, we found great diversity of PME in the A genome (70 PME: 41 PME type 1 and 29 PME type 2; 23 PMEI) and B-genome (60 PME: 38 PME type 1,22 PME type 2; 23 PMEI) within the parameters. Phylogenetic analysis classified the PME into six monophyletic groups. The gene family of PME and PMEI in banana genomes had a wide variety of patterns of structural, biochemical and functional characteristics.