All articles starting with R
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Ribeiro Couto
Ribeiro Couto (Rui Ribeiro Couto, 1898–1963) was a Brazilian diplomat, poet, and novelist, author of Cabocla, ambassador to Yugoslavia, and a member of the Brazilian Academy of Letters.
Ribeiroia
Ribeiroia is a genus of parasitic flatworm flukes that infects the developing limbs of frogs and salamanders, causing severe malformations like extra or missing limbs, a major focus of North American amphibian conservation since the 1990s.
Ribemont-sur-Ancre
Ribemont-sur-Ancre, a Celtic and Gallo-Roman sanctuary site in the Somme, France, holds Northern Gaul's largest excavated human bone assemblage, about 23,000 remains of 508 warriors, interpreted as a post-battle war monument.
Ribena
Ribena is a British blackcurrant soft drink brand launched in 1938 by Dr Vernon Charley, named from Ribes nigrum, given free to children as a WWII vitamin C supplement, made at Coleford since 1947, and owned by Suntory since 2013.
Ribes
Ribes (currants and gooseberries) is a genus of about 195 accepted shrub species in Grossulariaceae, native from subarctic to tropical American mountains, cultivated for black, red, and white currants and gooseberries, and alternate host of white pine blister rust.
Riblja Čorba
Riblja Čorba (Рибља Чорба), also rendered Riblja Corba, is a Serbian hard rock band formed in Belgrade in 1978, fronted by singer Bora Đorđević until his death in 2024.
Ribociclib
Ribociclib (Kisqali, LEE011), a Novartis oral CDK4/6 inhibitor, treats HR+/HER2- breast cancer with endocrine therapy; FDA approved 2017 for metastatic disease (MONALEESA-2) and 2024 for adjuvant early breast cancer (NATALEE).
Riboflavin
Riboflavin (vitamin B2) is a water-soluble B vitamin and precursor of the FAD and FMN coenzymes; RDA 1.3 mg men, 1.1 mg women; found in eggs, liver, milk; no UL set; used at 400 mg/day for migraine prevention.
Riboflavin as cofactor precursor
Riboflavin (vitamin B2) is the isoalloxazine-based precursor from which cells build the flavin cofactors FMN and FAD in two enzymatic steps, hydrogen carriers in more than 100 redox reactions of energy metabolism.
Riboflavin kinase
Riboflavin kinase (RFK, EC 2.7.1.26, flavokinase) phosphorylates vitamin B2 to FMN using ATP and Mg2+, the first step of FMN/FAD cofactor synthesis; monofunctional in eukaryotes, bifunctional (ribF) in bacteria, CTP-dependent variants in archaea.
Riboflavin kinase domain, bacterial/eukaryotic
Riboflavin kinase domain, bacterial/eukaryotic (InterPro IPR015865): conserved all-beta-barrel kinase domain phosphorylating riboflavin to FMN with ATP and Mg2+; standalone in eukaryotes, C-terminal module of bifunctional bacterial FAD synthetase.
Riboflavin synthase
Riboflavin synthase (EC 2.5.1.9), also called riboflavin synthetase, catalyzes the final step of vitamin B2 biosynthesis, a dismutation of two 6,7-dimethyl-8-ribityllumazine molecules into riboflavin; homotrimeric in bacteria, pentameric in some archaea, absent in humans.
Riboflavin transporter deficiency
Riboflavin transporter deficiency (RTD), formerly Brown-Vialetto-Van Laere and Fazio-Londe syndromes, is an autosomal recessive SLC52A2/SLC52A3 disorder causing progressive neuronopathy, treatable with high-dose oral riboflavin.
Riboflavin-responsive exercise intolerance
Riboflavin-responsive exercise intolerance (RREI, OMIM #616839) is a rare SLC25A32-related mitochondrial FAD transporter deficiency causing exercise intolerance with a MADD-like acylcarnitine profile, treatable with oral riboflavin.
Ribon Therapeutics
Ribon Therapeutics was a clinical-stage biotechnology company in Cambridge, Massachusetts, founded in 2015 to develop PARP inhibitors for cancer and inflammatory disease, and it ceased operations in 2024.
Ribonuclease
Ribonuclease (RNase), enzymes that cleave RNA phosphodiester bonds; RNase A gave the first enzyme mechanism (Mathias and Rabin, 1961) using His12/His119 general acid-base catalysis, while RNase H and RNase III are metal-dependent families.
Ribonuclease ageritin
Ribonuclease ageritin (Agt1) is a metal-dependent ribotoxin-like protein from the edible poplar mushroom Cyclocybe aegerita, the first basidiomycete ribotoxin; it cleaves the sarcin-ricin loop of 28S rRNA and shows antifungal, entomotoxic, and antitumor activities.
Ribonuclease CAF1
Ribonuclease CAF1 (Caf1/Pop2; human CNOT7/CNOT8) is a DEDD-superfamily poly(A)-specific 3'-5' exoribonuclease and catalytic deadenylase subunit of the Ccr4-Not mRNA decay complex, structurally distinct from TOE1/hCaf1z.
Ribonuclease D
Ribonuclease D (RNase D), rnd gene product of Escherichia coli, is a DEDD-family 3'→5' exoribonuclease that trims tRNA precursors and degrades damaged tRNA as a backup to RNase T and RNase PH.
Ribonuclease E
Ribonuclease E (RNase E, rne gene) is an essential bacterial endoribonuclease, a tetramer scaffolded in the membrane-bound RNA degradosome with PNPase, RhlB, and enolase, initiating tRNA processing and most mRNA decay in E. coli.
Ribonuclease H
Ribonuclease H (RNase H, EC 3.1.26.4), endoribonuclease family hydrolyzing RNA in RNA–DNA hybrids; classes H1, H2, H3; two-metal-ion Mg2+ catalysis; removes Okazaki primers and R-loops; RNase H2 mutations cause Aicardi-Goutières syndrome.
Ribonuclease III
Ribonuclease III (RNase III, EC 3.1.26.3, ribonuclease 3) is a Mg2+-dependent endonuclease that cleaves double-stranded RNA, leaving 2-nt 3′ overhangs; the E. coli rnc enzyme is the prototype of a family including Dicer and Drosha.
Ribonuclease P
Ribonuclease P (RNase P) is a ribonucleoprotein endonuclease, found in all three domains of life, whose RNA subunit catalyzes cleavage of the 5' leader from precursor tRNAs; protein-only PRORP and HARP variants exist in plants, mitochondria, and some bacteria.
Ribonuclease P subunit, Rpr2/Snm1/Rpp21
Rpr2/Snm1/Rpp21 (pfam04032) is a conserved RNase P protein subunit family: Rpr2 in yeast, RPP21 in humans and archaea, Snm1 in RNase MRP. It pairs with Rpp29, contacts the S domain of the RNase P RNA, and helps activate pre-tRNA 5' cleavage.
Ribonuclease P, Rpm2, mitochondrial
Rpm2 (RPM2, Rpm2p) is the 105-kDa nuclear-encoded protein subunit of Saccharomyces cerevisiae mitochondrial RNase P, paired with the mitochondrial Rpm1 RNA, with extra roles in translation, transcription, and P bodies.
Ribonuclease ribotoxin, alpha-sarcin type
Ribonuclease ribotoxin, alpha-sarcin type: fungal cytotoxic RNases (~150 aa, 17 kDa alpha-sarcin from Aspergillus giganteus) that cleave one bond in the sarcin-ricin loop of 28S rRNA, halting translation; relatives restrictocin, mitogillin, Aspf1, hirsutellin A.
Ribonuclease T
Ribonuclease T (RNase T, rnt gene product) is a 23 kDa DEDD-family 3'→5' exoribonuclease of E. coli that matures 5S/23S rRNA and tRNA ends, stops at CC residues, and also acts as a single-strand DNase.
Ribonucleases P/MRP protein subunit Pop1
Pop1 (POP1, Pop1p) is the largest shared protein subunit of eukaryotic RNase P and RNase MRP ribonucleoproteins, about 100 kDa in yeast and 114,709 Da in humans, acting as a scaffold for the catalytic RNA; distinct from the inflammasome-regulating PYD-only POP1.
Ribonucleotide reductase inhibitor
Ribonucleotide reductase inhibitors (RNR inhibitors, RR inhibitors) block the enzyme that makes deoxynucleotides for DNA synthesis. Key drugs include hydroxyurea, gemcitabine, and clofarabine, targeting RR1 or RR2 subunits in cancer therapy.
Ribophorin
Ribophorins (RPN1, RPN2): ER membrane proteins, homologs of yeast Ost1p and Swp1p, non-catalytic oligosaccharyltransferase subunits; RPN1 delivers substrates to STT3A and is upregulated in several cancers.