| Primary Identifier | IPR009091 | Type | Homologous_superfamily |
| Short Name | RCC1/BLIP-II |
| description | 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 β-propeller structure, although they differ in the number of strands per blade, BLIP-II having three antiparallel β-strands per blade, while RCC1 has four-stranded blades []. 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. |
