SummaryEarly genetic analysis of alternate recombination pathways inEscherichia coliidentified the RecE recombination pathway and the required exonuclease VIII encoded by therecEgene. Observations that not ail recombination events promoted by the RecE pathway requirerecAsuggest the existence of an additional homologous pairing protein besides RecA inE. coli.Genetic and biochemical analysis of therecEgene region indicates there are two partially overlapping genes,recEandrecT, encoding at least two proteins: exoVIII and the RecT protein. Biochemical analysis has shown that the RecT protein, in combination with exoVIII, promotes homologous pairing and strand exchange in reactions containing linear duplex DNA and homologous, circular, single‐stranded DNA as substrates. This reaction occurs in the absence of any high‐energy cofactor. These two proteins, RecT and exoVIII, appear to be members of a second class of homologous pairing proteins that are required in genetic recombination and differ from the class of homologous pairing proteins that includes RecA. Members of this second class of proteins appear to include both bacteriophage‐encoded proteins and proteins from eukaryotes and their vi