THE ABP LOCUS OF STREPTOCOCCUS-UBERIS ENCODES A PROTEIN HOMOLOGOUS TOPOLAR AMINO-ACID AND OPINE BINDING-PROTEINS OF GRAM-NEGATIVE BACTERIA

A gene locus abp was identified immediately upstream of the CAMP facto r gene cfu in Streptococcus uberis. An open reading frame capable of c oding for a 277-residue protein was identified. On the basis of sequen ce characteristics, the abp gene product is potentially a polar amino acid and opine binding component of an ATP-binding cassette type (ABC- type) transport system similar to those of Gram-negative bacteria. Thi s membrane protein is likely lipid modified at its amino terminus and was present in five S. uberis strains and one Streptococcus parauberis strain examined.