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Protein

Myosin IB heavy chain

Gene

myoB

Organism
Dictyostelium discoideum (Slime mold)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Myosin is a protein that binds to actin and has ATPase activity that is activated by actin. Myosin IB may have a role in chemotaxis and aggregation; it could serve to stabilize and even retract cortical structures, such as pseudopods and lamellopods. Involved in the whole cell motility of aggregation-stages cells. Overexpression results in significant decrease in the rate of cellular translocation and fluid-phase pinocytosis and abnormalities in the normal rearrangement of the actin cytoskeleton.3 Publications

Regions

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Nucleotide bindingi102 – 109ATPSequence analysis8

GO - Molecular functioni

  • actin-dependent ATPase activity Source: dictyBase
  • actin filament binding Source: dictyBase
  • ATP binding Source: dictyBase
  • microfilament motor activity Source: dictyBase
  • myosin I head/neck binding Source: dictyBase

GO - Biological processi

  • actin-myosin filament sliding Source: dictyBase
  • cell motility Source: dictyBase
  • chemotaxis Source: UniProtKB-KW
  • exocytosis Source: dictyBase
  • phagocytosis Source: dictyBase
  • phagosome reneutralization Source: dictyBase
  • regulation of post-lysosomal vacuole size Source: dictyBase
  • response to other organism Source: dictyBase
Complete GO annotation...

Keywords - Molecular functioni

Motor protein, Myosin

Keywords - Biological processi

Chemotaxis

Keywords - Ligandi

Actin-binding, ATP-binding, Nucleotide-binding

Names & Taxonomyi

Protein namesi
Recommended name:
Myosin IB heavy chain
Gene namesi
Name:myoB
Synonyms:dmiB, myoA
ORF Names:DDB_G0289117
OrganismiDictyostelium discoideum (Slime mold)
Taxonomic identifieri44689 [NCBI]
Taxonomic lineageiEukaryotaAmoebozoaMycetozoaDictyosteliidaDictyostelium
Proteomesi
  • UP000002195 Componentsi: Chromosome 5, Unassembled WGS sequence

Organism-specific databases

dictyBaseiDDB_G0289117. myoB.

Subcellular locationi

  • Cell projectionpseudopodium
  • Cytoplasmcell cortex

  • Note: Highest concentration just beneath the plasma membrane in the anterior pseudopod at the leading edge of the cell and at sites of cell-cell contact in both stationary and aggregation stage cells. Also found in macropinocytic structures.

GO - Cellular componenti

  • actomyosin Source: dictyBase
  • cell cortex Source: UniProtKB-SubCell
  • cell leading edge Source: dictyBase
  • phagocytic cup lip Source: dictyBase
  • phagocytic vesicle Source: dictyBase
  • phagocytic vesicle membrane Source: dictyBase
  • pseudopodium Source: UniProtKB-SubCell
  • unconventional myosin complex Source: dictyBase
Complete GO annotation...

Keywords - Cellular componenti

Cell projection, Cytoplasm

Pathology & Biotechi

Disruption phenotypei

Shows defects in pseudopod formation and translocation. Also shows slower speed of locomoting, aggregation-stage cells and significant reduction in initial rate of phagocytosis. MyoB and myoC double mutant exhibits profound defects in growth, endocytosis and rearrangement of F-actin. Expression of the full-length myoB heavy chain in these cells fully rescues the double mutant defects. myoB and myoD double mutant exhibits reduction in the speed of whole cell translocation. myoB, myoC and myoD triple mutant exhibits reduction in the speed of whole cell translocation.5 Publications

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi332S → A: Fail to complement the null phenotype. 2 Publications1
Mutagenesisi332S → E: Forms a complex in the presence and absence of Ca(2+). 2 Publications1

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001233661 – 1111Myosin IB heavy chainAdd BLAST1111

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei332PhosphoserineBy similarity1

Keywords - PTMi

Phosphoprotein

Proteomic databases

PaxDbiP34092.
PRIDEiP34092.

Expressioni

Developmental stagei

Rises dramatically during early development.1 Publication

Interactioni

Subunit structurei

Myosin I heavy chain is single-headed. Dimer of a heavy and a light chain. Inability to self-assemble into filaments.

GO - Molecular functioni

  • actin filament binding Source: dictyBase
  • myosin I head/neck binding Source: dictyBase

Protein-protein interaction databases

STRINGi44689.DDB0191351.

Structurei

3D structure databases

ProteinModelPortaliP34092.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini9 – 691Myosin motorAdd BLAST683
Domaini729 – 913TH1PROSITE-ProRule annotationAdd BLAST185
Domaini1053 – 1111SH3PROSITE-ProRule annotationAdd BLAST59

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni547 – 627Actin-bindingAdd BLAST81

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi922 – 1052Ala/Gly/Pro-rich (TH.2)Add BLAST131
Compositional biasi951 – 1015Asn-richAdd BLAST65
Compositional biasi955 – 965Poly-GlnAdd BLAST11

Domaini

Myosin tail domain binds directly to anionic phospholipid membranes; myosins I could therefore move actin relative to membranes and vice versa. TH.2 and SH3 bind tightly to F-actin; this together with the nucleotide-sensitive site in the head, allows single molecules of myosin I to cross-link actin filaments.

Sequence similaritiesi

Contains 1 myosin motor domain.Curated
Contains 1 SH3 domain.PROSITE-ProRule annotation
Contains 1 TH1 (class I myosin tail homology) domain.PROSITE-ProRule annotation

Keywords - Domaini

SH3 domain

Phylogenomic databases

eggNOGiKOG0162. Eukaryota.
COG5022. LUCA.
InParanoidiP34092.
KOiK10356.
OMAiHVILESN.
PhylomeDBiP34092.

Family and domain databases

Gene3Di3.40.50.300. 2 hits.
InterProiIPR001609. Myosin_head_motor_dom.
IPR010926. Myosin_TH1.
IPR027417. P-loop_NTPase.
IPR001452. SH3_domain.
[Graphical view]
PfamiPF00063. Myosin_head. 1 hit.
PF06017. Myosin_TH1. 1 hit.
PF00018. SH3_1. 1 hit.
[Graphical view]
PRINTSiPR00193. MYOSINHEAVY.
PR00452. SH3DOMAIN.
SMARTiSM00242. MYSc. 1 hit.
SM00326. SH3. 1 hit.
[Graphical view]
SUPFAMiSSF50044. SSF50044. 1 hit.
SSF52540. SSF52540. 1 hit.
PROSITEiPS51456. MYOSIN_MOTOR. 1 hit.
PS50002. SH3. 1 hit.
PS51757. TH1. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P34092-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MSKKVQAKQG TDDLVMLPKV SEDEICENLK KRYMNDFIYT NIGPVLISVN
60 70 80 90 100
PFRNLNNSGP DFIEAYRGKH AQEVPPHVYQ LAESAYRAMK NDQENQCVII
110 120 130 140 150
SGESGAGKTE AAKLIMGYVS AISGSTEKVE YVKHVILESN PLLEAFGNAK
160 170 180 190 200
TLRNNNSSRF GKYFEIQFDK AGDPVGGKIY NYLLEKSRVV YQNPGERNFH
210 220 230 240 250
IFYQLLAGAS AQEKRDYVLS SPESYYYLNQ SQCYTVDGIN DVSDYAEVRQ
260 270 280 290 300
AMDTIGLTAQ EQSDIIRIVA CVLHIGNIYF IEDDKGNAAI YDPNALELAA
310 320 330 340 350
SMLCIDSATL QNAILFRVIN TGGAGGAGNR RSTYNVPQNV EQANGTRDAL
360 370 380 390 400
ARTIYDRMFS WLVERVNQSL SYYKSPYQNV IGILDIFGFE IFEKNGFEQF
410 420 430 440 450
CINFVNEKLQ QFFIELTLKA EQEEYVREGI KWEPIKYFNN QIVCDLIEGK
460 470 480 490 500
SPPGIFSLLD DICSTLHAQS TGTDQKFLEK MAGIYDGHLH WRGMTGAFAI
510 520 530 540 550
KHYAGEVTYE AEGFSDKNKD TLFFDLIEAI QCSKMPFLAS LFNEDTGSLQ
560 570 580 590 600
KKRPTTAGFK IKTSAGELMK ALSQCTPHYI RCIKPNETKK AKDWENSRVK
610 620 630 640 650
HQVQYLGLLE NVRVRRAGFA YRNTFDKVLK RYKKLSSKTW GIWGEWKGDA
660 670 680 690 700
IEGCKTIFQD MNLEAGQWQL GKTKVFIRHP ETVFLLEEAL DKKDFDCTAK
710 720 730 740 750
IQKAFRNWKA KKHSLEQRAQ IAHMFKDKKE RQRNSIDRKF TSDYIDFENQ
760 770 780 790 800
FGLQEAMQNA HKKERVVFAD TVIKIDRRAK QKNYEMVLTD QALYFVEKSI
810 820 830 840 850
KKKVLVHTLI RRVGLREIKG VSISTLSDNV IVFHLPEHDQ VIENDKKTEI
860 870 880 890 900
IIVLVEYFKA IGGGSLNVQF SDRINYTLKK GEQKEISFQK SEQCPTLVVK
910 920 930 940 950
KGGKGLIGTI ASGLPSSTDS TPKNYNPNSM SQASSRPAPQ QSAGRGRGMP
960 970 980 990 1000
QGAGQPQPQQ PQQQQRPMPQ PQQGGGARPM PQPQQGGGAR PMGAPQQGGA
1010 1020 1030 1040 1050
PQQGAGRQLP QPTQQGGAPG GRGAPMGRGA PGGGPAGAGG RPLPTVAKPA
1060 1070 1080 1090 1100
PQPSRPTAKA LYDYDASSTD ELSFKEGDII FIVQKDNGGW TQGELKSGQK
1110
GWAPTNYLQY N
Length:1,111
Mass (Da):124,257
Last modified:December 4, 2007 - v2
Checksum:iB326A1DDF85B86AC
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti207A → R in AAA33229 (PubMed:2762320).Curated1
Sequence conflicti365R → K in AAA33229 (PubMed:2762320).Curated1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M26037 Genomic DNA. Translation: AAA33229.1.
AAFI02000130 Genomic DNA. Translation: EAL62866.1.
PIRiA33284.
RefSeqiXP_636382.1. XM_631290.1.

Genome annotation databases

EnsemblProtistsiEAL62866; EAL62866; DDB_G0289117.
GeneIDi8626983.
KEGGiddi:DDB_G0289117.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M26037 Genomic DNA. Translation: AAA33229.1.
AAFI02000130 Genomic DNA. Translation: EAL62866.1.
PIRiA33284.
RefSeqiXP_636382.1. XM_631290.1.

3D structure databases

ProteinModelPortaliP34092.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

STRINGi44689.DDB0191351.

Proteomic databases

PaxDbiP34092.
PRIDEiP34092.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblProtistsiEAL62866; EAL62866; DDB_G0289117.
GeneIDi8626983.
KEGGiddi:DDB_G0289117.

Organism-specific databases

dictyBaseiDDB_G0289117. myoB.

Phylogenomic databases

eggNOGiKOG0162. Eukaryota.
COG5022. LUCA.
InParanoidiP34092.
KOiK10356.
OMAiHVILESN.
PhylomeDBiP34092.

Miscellaneous databases

PROiP34092.

Family and domain databases

Gene3Di3.40.50.300. 2 hits.
InterProiIPR001609. Myosin_head_motor_dom.
IPR010926. Myosin_TH1.
IPR027417. P-loop_NTPase.
IPR001452. SH3_domain.
[Graphical view]
PfamiPF00063. Myosin_head. 1 hit.
PF06017. Myosin_TH1. 1 hit.
PF00018. SH3_1. 1 hit.
[Graphical view]
PRINTSiPR00193. MYOSINHEAVY.
PR00452. SH3DOMAIN.
SMARTiSM00242. MYSc. 1 hit.
SM00326. SH3. 1 hit.
[Graphical view]
SUPFAMiSSF50044. SSF50044. 1 hit.
SSF52540. SSF52540. 1 hit.
PROSITEiPS51456. MYOSIN_MOTOR. 1 hit.
PS50002. SH3. 1 hit.
PS51757. TH1. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiMYOB_DICDI
AccessioniPrimary (citable) accession number: P34092
Secondary accession number(s): Q54HY1
Entry historyi
Integrated into UniProtKB/Swiss-Prot: February 1, 1994
Last sequence update: December 4, 2007
Last modified: November 2, 2016
This is version 119 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)

Miscellaneousi

Keywords - Technical termi

Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Dictyostelium discoideum
    Dictyostelium discoideum: entries, gene names and cross-references to dictyBase
  2. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.