ID   TBA3_HOMAM              Reviewed;         451 AA.
AC   Q94572;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   03-AUG-2022, entry version 87.
DE   RecName: Full=Tubulin alpha-3 chain;
DE   AltName: Full=Alpha-III tubulin;
OS   Homarus americanus (American lobster).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Crustacea; Multicrustacea;
OC   Malacostraca; Eumalacostraca; Eucarida; Decapoda; Pleocyemata; Astacidea;
OC   Nephropoidea; Nephropidae; Homarus.
OX   NCBI_TaxID=6706;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=8666270; DOI=10.1016/0378-1119(96)00006-6;
RA   Demers D.M., Metcalf A.E., Talbot P., Hyman B.C.;
RT   "Multiple lobster tubulin isoforms are encoded by a simple gene family.";
RL   Gene 171:185-191(1996).
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.
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   -!- SUBCELLULAR LOCATION: Cytoplasm, cytoskeleton.
CC   -!- PTM: Undergoes a tyrosination/detyrosination cycle, the cyclic removal
CC       and re-addition of a C-terminal tyrosine residue by the enzymes tubulin
CC       tyrosine carboxypeptidase (TTCP) and tubulin tyrosine ligase (TTL),
CC       respectively. {ECO:0000250}.
CC   -!- PTM: Acetylation of alpha chains at Lys-40 stabilizes microtubules and
CC       affects affinity and processivity of microtubule motors. This
CC       modification has a role in multiple cellular functions, ranging from
CC       cell motility, cell cycle progression or cell differentiation to
CC       intracellular trafficking and signaling (By similarity). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the tubulin family. {ECO:0000305}.
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DR   EMBL; U68764; AAB08889.1; -; mRNA.
DR   AlphaFoldDB; Q94572; -.
DR   SMR; Q94572; -.
DR   PRIDE; Q94572; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-KW.
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; IPR002452; Alpha_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; PR01162; ALPHATUBULIN.
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.
PE   2: Evidence at transcript level;
KW   Acetylation; Cytoplasm; Cytoskeleton; GTP-binding; Microtubule;
KW   Nucleotide-binding.
FT   CHAIN           1..451
FT                   /note="Tubulin alpha-3 chain"
FT                   /id="PRO_0000048181"
FT   BINDING         142..148
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000255"
FT   SITE            451
FT                   /note="Involved in polymerization"
FT   MOD_RES         40
FT                   /note="N6-acetyllysine"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   451 AA;  50007 MW;  A3060D171DAD1597 CRC64;
     MRECISIHVG QAGAQMGNAC WELYCLEHGI QPDGQMPSDK TIGGGDDSFN TFFCETGAGK
     HVPRAVFVDL EPTVIDEIRT GVYRQLFHPE QLITGKEDAA NNYARGHYTI GKEIVDIVLD
     RIRKLADNCA GLQGFLIFHS FGGGTGSGFT SLLMERLSVD YGKKSKLEFA IYPAPQVATA
     VVEPYNSILT THTTLEHSDC AFMVDNEAIY DICRRNLDIE RPTYTNLNRL IGQIVSSITA
     SLRFDGALNV DLTEFQTNLV PYPRIHFPLV TYAPVISAEK AYHEQLSVSE ITNACFEPAN
     QMVKCDPRHG KYMACCLLYR GDVVPKDVNA AIATIKTKRS IQFVDWCPTG FKVGINYQPP
     TAVPGGDLAK VSRAVCMLSN TTAIAEAWAR LDHKFDLMYA KRAFVHWYVG EGMEEGEFTE
     AREDLAALEK DYEEVGVDSA DAEGEEEGEE Y