Members of this family are integral membrane proteins with 6 predicted transmembrane helices. Some members of this family have been shown to be essential for bacterial competence in uptake of extracellular DNA [1,4]. These proteins may transport DNA across the cell membrane. These proteins contain a highly conserved motif in the amino terminal transmembrane region that has two histidines that may form a metal binding site.

1: A novel determinant (comA) essential for natural transformation competence in Neisseria gonorrhoeae and the effect of a comA defect on pilin variation. Facius D, Meyer TF; Mol Microbiol 1993;10:699-712. PMID:7934834

2: Characterization of comE, a late competence operon of Bacillus subtilis required for the binding and uptake of transforming DNA. Hahn J, Inamine G, Kozlov Y, Dubnau D; Mol Microbiol 1993;10:99-111. PMID:7968523

3: Sequence of the rec-2 locus of Haemophilus influenzae: homologies to comE-ORF3 of Bacillus subtilis and msbA of Escherichia coli. Clifton SW, McCarthy D, Roe BA; Gene 1994;146:95-100. PMID:8063112

4: Isolation and characterization of three Streptococcus pneumoniae transformation-specific loci by use of a lacZ reporter insertion vector. Pestova EV, Morrison DA; J Bacteriol 1998;180:2701-2710. PMID:9573156