Nucleotide sequence of the myxobacterial hemagglutinin gene contains four homologous domains.

Myxococcus xanthus, a Gram-negative bacterium, has a complex life cycle that includes fruiting-body formation, a primitive form of multicellular development. Myxobacterial hemagglutinin (MBHA) is a lectin that is induced during the aggregation phase of fruiting-body formation. We have cloned the gene for MBHA and determined its sequence by the dideoxy chain-termination technique. The sequence data show the probable sites for translational initiation and termination and suggest that MBHA does not contain a cleaved leader signal peptide. The DNA sequence shows four strong internal homologies. The deduced amino acid sequence shows that the protein (Mr 27,920) consists of four highly conserved domains each consisting of 67 amino acids. Thus MBHA is physically multivalent in structure, a requirement for all hemagglutinins.