Confers DNA tethering and processivity to DNA polymerases and other proteins. Acts as a clamp, forming a ring around DNA (a reaction catalyzed by the clamp-loading complex) which diffuses in an ATP-independent manner freely and bidirectionally along dsDNA. Initially characterized for its ability to contact the catalytic subunit of DNA polymerase III (Pol III), a complex, multichain enzyme responsible for most of the replicative synthesis in bacteria; Pol III exhibits 3'-5' exonuclease proofreading activity. The beta chain is required for initiation of replication as well as for processivity of DNA replication (By similarity). Binds ds- and ssDNA (PubMed:22545130). Binds the antibiotic griselimycin and its derivatives with high affinity (1.0 x 10(-10) to 2.0 x 10(-10) M sec(-1)) (PubMed:26045430). Binding occurs in a hydrophobic cleft between domains 2 and 3, which have been shown to be responsible for binding DNA polymerases and other DNA-modifying proteins (PubMed:26045430). Forms a ring-shaped head-to-tail homodimer (PubMed:21219854, PubMed:22545130, PubMed:26045430) around DNA which binds and tethers DNA polymerases and other proteins to the DNA (PubMed:22545130). The DNA replisome complex has a single clamp-loading complex (3 tau and 1 each of delta, delta', psi and chi subunits) which binds 3 Pol III cores (1 core on the leading strand and 2 on the lagging strand) each with a beta sliding clamp dimer (By similarity). Additional proteins in the replisome are other copies of gamma, psi and chi, Ssb, DNA helicase and RNA primase (By similarity). Interacts with the tau/gamma subunit (dnaX) (PubMed:22545130). Strains that are resistant to griselimycin occur at a very low fequency and are associated with amplification of a 10.3 kb chromosomal segment containing this gene as well as the ori site, suggesting antibiotic resistance may be due to overexpression of the wild-type protein (PubMed:26045430). Belongs to the beta sliding clamp family.