P1B2

P1B2 is a designation used in molecular biology to refer to the P1B-2 subfamily of P-type ATPases, a group of membrane-embedded enzymes that couple ATP hydrolysis to the transport of metal ions across cellular membranes. Members of this subfamily are primarily involved in efflux or detoxification of copper and related metals in bacteria and archaea, contributing to metal homeostasis and resistance.

Structurally, P1B-2 enzymes share the canonical P-type ATPase architecture, with cytosolic A, P, and N domains and multiple transmembrane helices. The metal-binding site is typically located in transmembrane segments, with conserved motifs such as CPC or similar residues in TM6 that coordinate copper ions during transport. The transport cycle proceeds through phosphorylation and dephosphorylation of the P-domain, driven by ATP hydrolysis, enabling ion translocation across the membrane.

Genomic distribution of P1B-2 ATPases is broad, spanning diverse prokaryotes and often present in multiple copies or operons to support different metal-handling needs. Regulation of their expression is tied to copper status, with metal-responsive transcription factors modulating transcription in response to intracellular copper levels.

Biological significance and applications: P1B-2 ATPases are key for copper tolerance and can influence the pathogenicity of microbes by managing intracellular copper. They are studied as potential targets for antimicrobial strategies and for biotechnological applications that require metal homeostasis, bioremediation, or copper resistance traits. Environmental copper exposure can induce their expression, reflecting their role in adaptive metal management.

Other uses: In nonbiological contexts, the code P1B2 may appear in different disciplines as an identifier, but in scientific literature it most commonly denotes this copper-related subfamily of P-type ATPases.