DD21B_XENLA
ID DD21B_XENLA Reviewed; 800 AA.
AC Q9DF36; Q32NW4;
DT 04-MAR-2015, integrated into UniProtKB/Swiss-Prot.
DT 04-MAR-2015, sequence version 2.
DT 03-AUG-2022, entry version 109.
DE RecName: Full=Nucleolar RNA helicase 2-B {ECO:0000305};
DE EC=3.6.4.13 {ECO:0000250|UniProtKB:Q9NR30};
DE AltName: Full=DEAD box protein 21-B;
DE AltName: Full=Gu-alpha-B;
DE AltName: Full=Nucleolar RNA helicase Gu-B {ECO:0000303|PubMed:12851405};
DE Short=xGu-2 {ECO:0000303|PubMed:12851405};
DE AltName: Full=Nucleolar RNA helicase II-B {ECO:0000303|PubMed:12851405};
DE AltName: Full=RH II/Gu-B {ECO:0000303|PubMed:12851405};
GN Name=ddx21-b; Synonyms=ddx21;
OS Xenopus laevis (African clawed frog).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
OX NCBI_TaxID=8355;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, SUBCELLULAR LOCATION, AND TISSUE
RP SPECIFICITY.
RX PubMed=12851405; DOI=10.1074/jbc.m302258200;
RA Yang H., Zhou J., Ochs R.L., Henning D., Jin R., Valdez B.C.;
RT "Down-regulation of RNA helicase II/Gu results in the depletion of 18 and
RT 28 S rRNAs in Xenopus oocyte.";
RL J. Biol. Chem. 278:38847-38859(2003).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC TISSUE=Embryo;
RG NIH - Xenopus Gene Collection (XGC) project;
RL Submitted (NOV-2005) to the EMBL/GenBank/DDBJ databases.
CC -!- FUNCTION: RNA helicase that acts as a sensor of the transcriptional
CC status of both RNA polymerase (Pol) I and II: promotes ribosomal RNA
CC (rRNA) processing and transcription from polymerase II (Pol II) (By
CC similarity). Binds various RNAs, such as rRNAs, snoRNAs, 7SK and, at
CC lower extent, mRNAs (By similarity). In the nucleolus, localizes to
CC rDNA locus, where it directly binds rRNAs and snoRNAs, and promotes
CC rRNA transcription, processing and modification (PubMed:12851405)
CC (Probable). Required for rRNA 2'-O-methylation, possibly by promoting
CC the recruitment of late-acting snoRNAs SNORD56 and SNORD58 with pre-
CC ribosomal complexes (By similarity). In the nucleoplasm, binds 7SK RNA
CC and is recruited to the promoters of Pol II-transcribed genes: acts by
CC facilitating the release of P-TEFb from inhibitory 7SK snRNP in a
CC manner that is dependent on its helicase activity, thereby promoting
CC transcription of its target genes (By similarity). Required to prevent
CC R-loop-associated DNA damage and transcription-associated genomic
CC instability (By similarity). {ECO:0000250|UniProtKB:Q9NR30,
CC ECO:0000305|PubMed:12851405}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + H2O = ADP + H(+) + phosphate; Xref=Rhea:RHEA:13065,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:30616,
CC ChEBI:CHEBI:43474, ChEBI:CHEBI:456216; EC=3.6.4.13;
CC Evidence={ECO:0000250|UniProtKB:Q9NR30};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:13066;
CC Evidence={ECO:0000250|UniProtKB:Q9NR30};
CC -!- SUBCELLULAR LOCATION: Nucleus, nucleolus {ECO:0000269|PubMed:12851405}.
CC Nucleus, nucleoplasm {ECO:0000250|UniProtKB:Q9NR30}. Cytoplasm, cytosol
CC {ECO:0000250|UniProtKB:Q9JIK5}. Mitochondrion
CC {ECO:0000250|UniProtKB:Q9JIK5}.
CC -!- TISSUE SPECIFICITY: Widely expressed. Expressed at higher level in
CC stomach. Expressed at lower level compared to ddx21-a.
CC {ECO:0000269|PubMed:12851405}.
CC -!- SIMILARITY: Belongs to the DEAD box helicase family. DDX21/DDX50
CC subfamily. {ECO:0000305}.
CC -!- SEQUENCE CAUTION:
CC Sequence=AAI08449.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};
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DR EMBL; AF302422; AAG22818.1; -; mRNA.
DR EMBL; BC108448; AAI08449.1; ALT_INIT; mRNA.
DR RefSeq; NP_001082033.1; NM_001088564.1.
DR AlphaFoldDB; Q9DF36; -.
DR SMR; Q9DF36; -.
DR GeneID; 398188; -.
DR KEGG; xla:398188; -.
DR CTD; 398188; -.
DR Xenbase; XB-GENE-1012552; ddx21.L.
DR OrthoDB; 1139373at2759; -.
DR Proteomes; UP000186698; Chromosome 7L.
DR Bgee; 398188; Expressed in lung and 19 other tissues.
DR GO; GO:0005829; C:cytosol; ISS:UniProtKB.
DR GO; GO:0005739; C:mitochondrion; IEA:UniProtKB-SubCell.
DR GO; GO:0005730; C:nucleolus; IDA:UniProtKB.
DR GO; GO:0005654; C:nucleoplasm; ISS:UniProtKB.
DR GO; GO:0097322; F:7SK snRNA binding; ISS:UniProtKB.
DR GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR GO; GO:0016887; F:ATP hydrolysis activity; IEA:RHEA.
DR GO; GO:0003724; F:RNA helicase activity; ISS:UniProtKB.
DR GO; GO:0019843; F:rRNA binding; ISS:UniProtKB.
DR GO; GO:0030515; F:snoRNA binding; ISS:UniProtKB.
DR GO; GO:0062176; P:R-loop disassembly; ISS:UniProtKB.
DR GO; GO:0006364; P:rRNA processing; IMP:UniProtKB.
DR GO; GO:0006366; P:transcription by RNA polymerase II; ISS:UniProtKB.
DR Gene3D; 3.40.50.300; -; 2.
DR InterPro; IPR011545; DEAD/DEAH_box_helicase_dom.
DR InterPro; IPR012562; GUCT.
DR InterPro; IPR014001; Helicase_ATP-bd.
DR InterPro; IPR001650; Helicase_C.
DR InterPro; IPR027417; P-loop_NTPase.
DR InterPro; IPR035979; RBD_domain_sf.
DR Pfam; PF00270; DEAD; 1.
DR Pfam; PF08152; GUCT; 1.
DR Pfam; PF00271; Helicase_C; 1.
DR SMART; SM00487; DEXDc; 1.
DR SMART; SM00490; HELICc; 1.
DR SUPFAM; SSF52540; SSF52540; 1.
DR SUPFAM; SSF54928; SSF54928; 1.
DR PROSITE; PS51192; HELICASE_ATP_BIND_1; 1.
DR PROSITE; PS51194; HELICASE_CTER; 1.
DR PROSITE; PS51195; Q_MOTIF; 1.
PE 2: Evidence at transcript level;
KW ATP-binding; Cytoplasm; Helicase; Hydrolase; Mitochondrion;
KW Nucleotide-binding; Nucleus; Reference proteome; Repeat; RNA-binding;
KW rRNA processing; Transcription.
FT CHAIN 1..800
FT /note="Nucleolar RNA helicase 2-B"
FT /id="PRO_0000432389"
FT DOMAIN 252..431
FT /note="Helicase ATP-binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00541"
FT DOMAIN 464..620
FT /note="Helicase C-terminal"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00542"
FT REGION 1..200
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 750..800
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOTIF 221..249
FT /note="Q motif"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00552"
FT MOTIF 374..377
FT /note="DEAD box"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00541"
FT COMPBIAS 9..47
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 49..63
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 114..132
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 160..174
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 175..200
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 751..777
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 265..272
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00541"
FT CONFLICT 367
FT /note="A -> V (in Ref. 2; AAI08449)"
FT /evidence="ECO:0000305"
FT CONFLICT 382
FT /note="V -> M (in Ref. 2; AAI08449)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 800 AA; 89378 MW; 19BDE72EE85A4E86 CRC64;
MPGKVYTDEM EGKSIKKKKL TETPLPKLKK RKMQNGETED LDLEHVTESV NGEINNNNPT
PKLKKNKKPA PKSDLSETAE QCDGEQPDPS TPTPKKVKKK KLKEGKEDSD AQEETNISLS
SQGGQCDGEQ PDPSTPTPKK IKKKKLKEGK EDSDAQEETD ISEPQMNGVK SVKKSKKNTT
GDEPAPKKRK TDTSEITAAN ECEEKELTKE EEEIKKEKID GDFSKFPISK DTIKNLQAKG
VTYLFPIQSK TFHTVYSGKD VVVQARTGTG KTFSFGIPLV ERLSEDQQPL ARGRAPRVII
LTPTRELAIQ ITNELRSMTK KLKVACFYGG TPYQQQVFAI KDGIDFLVGT PGRIRDLVQN
YRLDLTALKH VVLDEVDMMF DVGFSEQVEE ILSVRYKPDP EENPQTLLFS ATCPDWMYNV
AKKYMRKQYE KVDLVGHRSQ KAAITVEHLA IECNRSQKAA VLGDIVQVYS GSHGKTIIFC
DSKLQAHELS TNCGSLKQSA KPLHGDLQQK EREVVLKGFR QGTFEVLIAT NVAARGLDIP
EVDLVVLYSA PKEADAYVHR SGRTGRAGRT GVCISLYEPW EKHYLRNVER STGITFKRVG
IPSLMNVAKS SSADAIKSLD TVPADVIEHF KEYAQELIEK KGALTALAAA LAHISGATSI
KQRSLLNMEA GYMTITLKSS VPIHNLSYAW RSIKEQLGED VDSKIHRMCL LKDSMGVCFD
VRSEDLQSMQ ESWSDTRRWQ FTITTELPEI QESERSFDGP RNRSFGGRGR RPFDRRNNSR
NSSGGGGGRR GRSGGFRRGR
