Conserved domain analysis of A. flavus UDP-glucose 4-epimerase isoforms. (A) The RefSeq protein of the UDP-galactose 4 epimerase consisted of four exons. The first two were constitutive exons. All Mascot, OMSSA, X! Tandem, and InsPecT confirmed the existence of the RefSeq protein based on different numbers of shared and RefSeq-specific peptides. The 5 common and 9 RefSeq-specific peptides detected by Mascot are illustrated. Two functional domains, 3-ketoacyl-(acyl-carrier-protein) reductase [CDD: PRK12825] and UDP-glucose 4-epimerase [CDD: PLN02240], were recognized through searching the sequence against the Conserved Domain Database (version 2.23) and an E-value threshold of 0.01. (B) Peptide FAVETAITDVINAQR was used to conclude the alternative exon in the putative isoform. Short chain dehydrogenase [CDD: pfam00106] domain was found in the sequence of the alternatively spliced variant via searching the CDD database. Mapped 454 sequence reads are labeled in purple. RefSeq protein-specific, splice variant-specific, and commonly shared peptides are labeled in yellow, blue and green, respectively.