This domain family is found in bacteria, and is approximately 140 amino acids in length. The family is found in association with Pfam:PF00004. Domains I-III are shared between the tau and the gamma subunits, while most of the DnaB-binding Domain IV and all of the alpha-interacting Domain V are unique to tau. The extreme C-terminal region of this domain 5 is the part which interacts with the alpha subunit of the DNA polymerase III holoenzyme.

1: tau binds and organizes Escherichia coli replication through distinct domains. Partial proteolysis of terminally tagged tau to determine candidate domains and to assign domain V as the alpha binding domain. Gao D, McHenry CS; J Biol Chem. 2001;276:4433-4440. PMID:11078743

2: The unstructured C-terminus of the tau subunit of Escherichia coli DNA polymerase III holoenzyme is the site of interaction with the alpha subunit. Jergic S, Ozawa K, Williams NK, Su XC, Scott DD, Hamdan SM, Crowther JA, Otting G, Dixon NE; Nucleic Acids Res. 2007;35:2813-2824. PMID:17355988

3: Genomic insights into Mn(II) oxidation by the marine alphaproteobacterium Aurantimonas sp. strain SI85-9A1. Dick GJ, Podell S, Johnson HA, Rivera-Espinoza Y, Bernier-Latmani R, McCarthy JK, Torpey JW, Clement BG, Gaasterland T, Tebo BM; Appl Environ Microbiol. 2008;74:2646-2658. PMID:18344346