ID   TBBN_GUITH              Reviewed;         441 AA.
AC   Q9SEV2; Q9ZTL3;
DT   02-MAY-2006, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2001, sequence version 2.
DT   03-AUG-2022, entry version 99.
DE   RecName: Full=Tubulin beta chain, nucleomorph;
DE   AltName: Full=Nucleomorph beta-tubulin;
GN   Name=tubB; Synonyms=btubNM;
OS   Guillardia theta (Cryptophyte) (Cryptomonas phi).
OG   Nucleomorph.
OC   Eukaryota; Cryptophyceae; Pyrenomonadales; Geminigeraceae; Guillardia.
OX   NCBI_TaxID=55529;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=11323671; DOI=10.1038/35074092;
RA   Douglas S.E., Zauner S., Fraunholz M., Beaton M., Penny S.L., Deng L.-T.,
RA   Wu X., Reith M.E., Cavalier-Smith T., Maier U.-G.;
RT   "The highly reduced genome of an enslaved algal nucleus.";
RL   Nature 410:1091-1096(2001).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 16-402.
RX   PubMed=10486984; DOI=10.1093/oxfordjournals.molbev.a026221;
RA   Keeling P.J., Deane J.A., Hink-Schauer C., Douglas S.E., Maier U.-G.,
RA   McFadden G.I.;
RT   "The secondary endosymbiont of the cryptomonad Guillardia theta contains
RT   alpha-, beta-, and gamma-tubulin genes.";
RL   Mol. Biol. Evol. 16:1308-1313(1999).
CC   -!- FUNCTION: Tubulin is the major constituent of microtubules. It binds
CC       two moles of GTP, one at an exchangeable site on the beta chain and one
CC       at a non-exchangeable site on the alpha chain (By similarity).
CC       {ECO:0000250}.
CC   -!- SUBUNIT: Dimer of alpha and beta chains. A typical microtubule is a
CC       hollow water-filled tube with an outer diameter of 25 nm and an inner
CC       diameter of 15 nM. Alpha-beta heterodimers associate head-to-tail to
CC       form protofilaments running lengthwise along the microtubule wall with
CC       the beta-tubulin subunit facing the microtubule plus end conferring a
CC       structural polarity. Microtubules usually have 13 protofilaments but
CC       different protofilament numbers can be found in some organisms and
CC       specialized cells.
CC   -!- SIMILARITY: Belongs to the tubulin family. {ECO:0000305}.
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DR   EMBL; AF083031; AAK39778.1; -; Genomic_DNA.
DR   EMBL; AF050094; AAD02573.1; -; Genomic_DNA.
DR   PIR; E90136; E90136.
DR   RefSeq; XP_001713469.1; XM_001713417.1.
DR   AlphaFoldDB; Q9SEV2; -.
DR   SMR; Q9SEV2; -.
DR   PRIDE; Q9SEV2; -.
DR   GeneID; 857251; -.
DR   GO; GO:0005874; C:microtubule; IEA:UniProtKB-KW.
DR   GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR   GO; GO:0005200; F:structural constituent of cytoskeleton; IEA:InterPro.
DR   GO; GO:0007017; P:microtubule-based process; IEA:InterPro.
DR   Gene3D; 1.10.287.600; -; 1.
DR   Gene3D; 3.30.1330.20; -; 1.
DR   Gene3D; 3.40.50.1440; -; 1.
DR   InterPro; IPR013838; Beta-tubulin_BS.
DR   InterPro; IPR002453; Beta_tubulin.
DR   InterPro; IPR008280; Tub_FtsZ_C.
DR   InterPro; IPR000217; Tubulin.
DR   InterPro; IPR037103; Tubulin/FtsZ-like_C.
DR   InterPro; IPR018316; Tubulin/FtsZ_2-layer-sand-dom.
DR   InterPro; IPR036525; Tubulin/FtsZ_GTPase_sf.
DR   InterPro; IPR023123; Tubulin_C.
DR   InterPro; IPR017975; Tubulin_CS.
DR   InterPro; IPR003008; Tubulin_FtsZ_GTPase.
DR   PANTHER; PTHR11588; PTHR11588; 1.
DR   Pfam; PF00091; Tubulin; 1.
DR   Pfam; PF03953; Tubulin_C; 1.
DR   PRINTS; PR01163; BETATUBULIN.
DR   PRINTS; PR01161; TUBULIN.
DR   SMART; SM00864; Tubulin; 1.
DR   SMART; SM00865; Tubulin_C; 1.
DR   SUPFAM; SSF52490; SSF52490; 1.
DR   SUPFAM; SSF55307; SSF55307; 1.
DR   PROSITE; PS00227; TUBULIN; 1.
DR   PROSITE; PS00228; TUBULIN_B_AUTOREG; 1.
PE   3: Inferred from homology;
KW   GTP-binding; Microtubule; Nucleotide-binding.
FT   CHAIN           1..441
FT                   /note="Tubulin beta chain, nucleomorph"
FT                   /id="PRO_0000233349"
FT   BINDING         140..146
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   441 AA;  49778 MW;  3ABA2D557D0319FD CRC64;
     MREIVHVQVG QCGNQIGAKF WEVISHEHGV DTNGTYFGNK DNQIEKIDVY YNEVSGNRFV
     PRAVLVDLEP GTMDSVRASN YGRLFRPDNF VFGQSGAGNN WAKGHYTEGA ELIESAMDII
     RKESEQCECL QGFQIAHSLG GGTGSGMGTL LISKIREEYP DRMMCTYSVV PSPKVSDTVV
     EPYNCTLSIH QLVENADEVF CIDNEALYDI CFRTLKLVTP SYGDLNHLVS AVMSGITCSL
     RFPGQLNADL RKLAVNLVPF PRLHFFMVGF APLGSRGSQQ YRSMTVNDLT QQMFDSKNMM
     AACDPKNGRY LTAAAYFRGK ISTKEVDDQM IEIQNKQSEH FVEWIPHNIK SSVCDIPPKG
     MKMSAAFIGN STSIQELFKR VGEQFQAMFR RKAFLHWYTG EGMDEMEFTE AESNMQDLVS
     EYQQYQDAKM DNDAFEDQDL Y