Expression in Escherichia coli of the putative N-acetylneuraminate lyase gene (nanA) from Haemophilus influenzae: overproduction, purification, and crystallization.

The cloning and expression of the Haemophilus influenzae gene, nanA, for the putative N-acetylneuraminate lyase enzyme, also known as N-acetylneuraminic acid aldolase or sialic acid aldolase, are reported. The gene was isolated from ATCC type strain 49247 and cloned into the Escherichia coli expression vector pKKtac, which contained the strong tac promoter. Gene expression was compared with the homologous E.