Homologous Superfamily

Regulator of chromosome condensation 1/beta-lactamase-inhibitor protein II (IPR009091)

Short name: RCC1/BLIP-II

Overlapping entries


The beta-lactamase-inhibitor protein II (BLIP-II) is a secreted protein produced by the soil bacteria Streptomyces exfoliates SMF19. BLIP-II acts as a potent inhibitor of beta-lactamases such as TEM-1, which is the most widespread resistance enzyme to penicillin antibiotics. BLIP-II binds competitively to TEM-1, but no direct contacts are made with TEM-1 active site residues. BLIP-II shows no sequence similarity with BLIP, even though both bind to and inhibit TEM-1. However, BLIP-II does share significant sequence identity with the regulator of chromosome condensation (RCC1) family of proteins. These two families are clearly related, both having a seven-bladed beta-propeller structure, although they differ in the number of strands per blade, BLIP-II having three antiparallel beta-strands per blade, while RCC1 has four-stranded blades [PMID: 11573088]. RCC1 is a eukaryotic nuclear protein that acts as a guanine nucleotide exchange factor for Ran, a member of the Ras GTPase family. RCC1 mediates a Ran-GTP gradient necessary for the regulation of spindle formation and nuclear assembly during mitosis, as well as for the transport of macromolecules across the nuclear membrane during interphase.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.