A cDNA clone encoding a pectinacetylesterase (PAE) was isolated from 3-day-old mung bean seedlings using PCR-based techniques. Degenerate oligonucleotide primers were designed according to the N-terminus and internal peptides from the purified PAE. The full-length clone of 1453 bp codes for a signal peptide of 24 amino acids and a mature protein of 375 amino acids. The Mr and the pI of the cDNA-deduced amino acid sequence agree with the values estimated for the purified enzyme. No significant sequence identity between the PAE and any known protein could be found in the databases. Northern analysis revealed developmentally regulated expression of the mRNA in mung been seedlings.