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O23680 (TOC33_ARATH) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 97. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (3) | Third-party data text xml rdf/xml gff fasta
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Names and origin

Protein namesRecommended name:
Translocase of chloroplast 33, chloroplastic

Short name=AtToc33
EC=3.6.5.-
Alternative name(s):
33 kDa chloroplast outer envelope protein
Plastid protein import 1
Gene names
Name:TOC33
Synonyms:PPI1
Ordered Locus Names:At1g02280
ORF Names:T7I23.11
OrganismArabidopsis thaliana (Mouse-ear cress) [Reference proteome]
Taxonomic identifier3702 [NCBI]
Taxonomic lineageEukaryotaViridiplantaeStreptophytaEmbryophytaTracheophytaSpermatophytaMagnoliophytaeudicotyledonsGunneridaePentapetalaerosidsmalvidsBrassicalesBrassicaceaeCamelineaeArabidopsis

Protein attributes

Sequence length297 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

GTPase involved in protein precursor import into chloroplasts. Seems to recognize chloroplast-destined precursor proteins and regulate their presentation to the translocation channel through GTP hydrolysis. Binds GTP, GDP, XTP, but not ATP. Probably specialized in the import of nuclear encoded photosynthetic preproteins from the cytoplasm to the chloroplast, especially during early development stages. Ref.7 Ref.9 Ref.10 Ref.11 Ref.12 Ref.14 Ref.16 Ref.18 Ref.19 Ref.20

Cofactor

Binds 1 magnesium ion by subunit.

Subunit structure

Homodimer, heterodimer with TOC34 and TOC159, and monomer. The homodimerization and the dimerization with TOC159 require the binding of GTP on Arg-130, and a hypothetical coGAP factor. The dimeric form has a higher GTPase activity than the monomeric form. Part of the TOC core complex that includes 1 protein for the specific recognition of transit peptides surrounded by a ring composed of four proteins forming translocation channels, and four to five GTP-binding proteins providing energy. This core complex can interact with components of the TIC complex to form a larger import complex. Chloroplastic protein precursor such as prSS (precursor of the RuBisCO small subunit) interacts with these complexes. The TOC complex contains a specific subset of polar lipids such as digalactosyldiacylglyceride (DGDG), phosphatidylcholine (PC) and phosphatidylglycerol (PG). Interacts at least with TOC75-3. Forms large complexes including TOC33, pPORA and OEP161 during pPORA import into plastids at the plastid envelope membrane. Ref.1 Ref.8 Ref.9 Ref.11 Ref.12 Ref.17 Ref.22 Ref.23 Ref.24

Subcellular location

Plastidchloroplast outer membrane; Single-pass membrane protein. Note: May contain beta barrel transmembrane regions. Ref.1 Ref.12 Ref.13 Ref.15

Tissue specificity

Mostly expressed in seedlings and flowers, and, to a lower extent, in roots, stems, and leaves. Ref.1 Ref.14

Developmental stage

Mostly expressed in photosynthetic tissues undergoing rapid growth. Observed in cotyledons and vascular tissues of hypocotyls of young seedling. In roots, restricted to apical and lateral meristems, and vascular bundles. In stems, mostly detected in the upper part. Expressed in young and middle-aged leaves. In flowers, confined to sepals. Ref.1 Ref.14

Induction

Up-regulated by CIA2 in leaves. Induced in light but repressed in darkness. Ref.6 Ref.14

Post-translational modification

Phosphorylated by a kinase present in the outer envelope of chloroplast. When Ser-181 is phosphorylated, the binding to preprotein, GTP and GDP is inhibited, and thus, GTPase activity is repressed. Ref.9 Ref.18 Ref.20

Disruption phenotype

Plants exhibits a pale yellowish phenotype. Ref.1 Ref.7 Ref.14

Sequence similarities

Belongs to the TOC34 family.

Biophysicochemical properties

Kinetic parameters:

KM=290 nM for GDP (at pH 7.4) Ref.9 Ref.21

KM=5.7 µM for GTP (at pH 7.6 and 25 degrees Celsius)

Vmax=1040 nmol/min/µg enzyme with GTP as substrate (at pH 7.4)

Binary interactions

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Initiator methionine11Removed By similarity
Chain2 – 297296Translocase of chloroplast 33, chloroplastic
PRO_0000352655

Regions

Transmembrane37 – 5317Helical; Potential
Nucleotide binding46 – 516GTP
Nucleotide binding65 – 706GTP
Nucleotide binding208 – 2092GTP
Region65 – 684Homodimerization By similarity
Region125 – 1306Homodimerization

Sites

Metal binding501Magnesium
Metal binding681Magnesium
Binding site1601GTP; via amide nitrogen

Amino acid modifications

Modified residue1811Phosphoserine Ref.9 Ref.18 Ref.20

Experimental info

Mutagenesis45 – 506GGVGKS → RGVGNR: Reduced GTPase activity and impaired interaction with TOC159. Ref.12
Mutagenesis1301R → A: Loss of homidimerization and heterodimerization with TOC159, reduction of GTPase activity. Ref.11 Ref.22 Ref.23
Mutagenesis1701S → A: Normal phosphorylation. Ref.9
Mutagenesis1751S → A: Normal phosphorylation. Ref.9
Mutagenesis1811S → A: Loss of phosphorylation, normal activity. Ref.9 Ref.18
Mutagenesis1811S → D or E: According to PubMed:16412428, supposed to mimic the effects of phosphoserine, but normal activity. Ref.9 Ref.18
Mutagenesis1811S → T: Phosphothreonine instead of phosphoserine. Ref.9 Ref.18
Mutagenesis1901S → A: Normal phosphorylation. Ref.9
Mutagenesis2001S → A: Normal phosphorylation. Ref.9
Mutagenesis2081E → Q: Normal GTPase activity, but weaker nucleotide binding. Ref.10
Mutagenesis2171D → N: Normal GTPase activity. Ref.10
Mutagenesis2191D → N: Normal GTPase activity. Ref.10
Mutagenesis2201E → Q: Normal GTPase activity. Ref.10
Sequence conflict1471G → A in AAK68809. Ref.4

Secondary structure

........................................ 297
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
O23680 [UniParc].

Last modified January 1, 1998. Version 1.
Checksum: E48892E123BA412D

FASTA29732,925
        10         20         30         40         50         60 
MGSLVREWVG FQQFPAATQE KLIEFFGKLK QKDMNSMTVL VLGKGGVGKS STVNSLIGEQ 

        70         80         90        100        110        120 
VVRVSPFQAE GLRPVMVSRT MGGFTINIID TPGLVEAGYV NHQALELIKG FLVNRTIDVL 

       130        140        150        160        170        180 
LYVDRLDVYR VDELDKQVVI AITQTFGKEI WCKTLLVLTH AQFSPPDELS YETFSSKRSD 

       190        200        210        220        230        240 
SLLKTIRAGS KMRKQEFEDS AIAVVYAENS GRCSKNDKDE KALPNGEAWI PNLVKAITDV 

       250        260        270        280        290 
ATNQRKAIHV DKKMVDGSYS DDKGKKLIPL IIGAQYLIVK MIQGAIRNDI KTSGKPL 

« Hide

References

« Hide 'large scale' references
[1]"Functional analysis of the two Arabidopsis homologues of Toc34, a component of the chloroplast protein import apparatus."
Gutensohn M., Schulz B.I., Nicolay P., Fluegge U.-I.
Plant J. 23:771-783(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], CHARACTERIZATION, DISRUPTION PHENOTYPE, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, DEVELOPMENTAL STAGE, INTERACTION WITH TOC75.
Strain: cv. Columbia.
Tissue: Etiolated seedling.
[2]"Sequence and analysis of chromosome 1 of the plant Arabidopsis thaliana."
Theologis A., Ecker J.R., Palm C.J., Federspiel N.A., Kaul S., White O., Alonso J., Altafi H., Araujo R., Bowman C.L., Brooks S.Y., Buehler E., Chan A., Chao Q., Chen H., Cheuk R.F., Chin C.W., Chung M.K. expand/collapse author list , Conn L., Conway A.B., Conway A.R., Creasy T.H., Dewar K., Dunn P., Etgu P., Feldblyum T.V., Feng J.-D., Fong B., Fujii C.Y., Gill J.E., Goldsmith A.D., Haas B., Hansen N.F., Hughes B., Huizar L., Hunter J.L., Jenkins J., Johnson-Hopson C., Khan S., Khaykin E., Kim C.J., Koo H.L., Kremenetskaia I., Kurtz D.B., Kwan A., Lam B., Langin-Hooper S., Lee A., Lee J.M., Lenz C.A., Li J.H., Li Y.-P., Lin X., Liu S.X., Liu Z.A., Luros J.S., Maiti R., Marziali A., Militscher J., Miranda M., Nguyen M., Nierman W.C., Osborne B.I., Pai G., Peterson J., Pham P.K., Rizzo M., Rooney T., Rowley D., Sakano H., Salzberg S.L., Schwartz J.R., Shinn P., Southwick A.M., Sun H., Tallon L.J., Tambunga G., Toriumi M.J., Town C.D., Utterback T., Van Aken S., Vaysberg M., Vysotskaia V.S., Walker M., Wu D., Yu G., Fraser C.M., Venter J.C., Davis R.W.
Nature 408:816-820(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: cv. Columbia.
[3]The Arabidopsis Information Resource (TAIR)
Submitted (APR-2011) to the EMBL/GenBank/DDBJ databases
Cited for: GENOME REANNOTATION.
Strain: cv. Columbia.
[4]"Empirical analysis of transcriptional activity in the Arabidopsis genome."
Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J., Southwick A.M., Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F., Karlin-Newmann G., Liu S.X., Lam B., Sakano H., Wu T., Yu G. expand/collapse author list , Miranda M., Quach H.L., Tripp M., Chang C.H., Lee J.M., Toriumi M.J., Chan M.M., Tang C.C., Onodera C.S., Deng J.M., Akiyama K., Ansari Y., Arakawa T., Banh J., Banno F., Bowser L., Brooks S.Y., Carninci P., Chao Q., Choy N., Enju A., Goldsmith A.D., Gurjal M., Hansen N.F., Hayashizaki Y., Johnson-Hopson C., Hsuan V.W., Iida K., Karnes M., Khan S., Koesema E., Ishida J., Jiang P.X., Jones T., Kawai J., Kamiya A., Meyers C., Nakajima M., Narusaka M., Seki M., Sakurai T., Satou M., Tamse R., Vaysberg M., Wallender E.K., Wong C., Yamamura Y., Yuan S., Shinozaki K., Davis R.W., Theologis A., Ecker J.R.
Science 302:842-846(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
Strain: cv. Columbia.
[5]"Arabidopsis ORF clones."
Shinn P., Chen H., Kim C.J., Quinitio C., Ecker J.R.
Submitted (JUN-2006) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
Strain: cv. Columbia.
[6]"Leaf-specific upregulation of chloroplast translocon genes by a CCT motif-containing protein, CIA2."
Sun C.-W., Chen L.-J., Lin L.-C., Li H.-M.
Plant Cell 13:2053-2061(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: INDUCTION.
[7]"Chloroplast protein translocon components atToc159 and atToc33 are not essential for chloroplast biogenesis in guard cells and root cells."
Yu T.-S., Li H.-M.
Plant Physiol. 127:90-96(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, DISRUPTION PHENOTYPE.
[8]"The targeting of the atToc159 preprotein receptor to the chloroplast outer membrane is mediated by its GTPase domain and is regulated by GTP."
Smith M.D., Hiltbrunner A., Kessler F., Schnell D.J.
J. Cell Biol. 159:833-843(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: INTERACTION WITH TOC159.
[9]"Two Toc34 homologues with different properties."
Jelic M., Soll J., Schleiff E.
Biochemistry 42:5906-5916(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, BIOPHYSICOCHEMICAL PROPERTIES, PHOSPHORYLATION AT SER-181, DIMERIZATION WITH TOC34, MUTAGENESIS OF SER-170; SER-175; SER-181; SER-190 AND SER-200.
[10]"Unusual nucleotide-binding properties of the chloroplast protein import receptor, atToc33."
Aronsson H., Combe J., Jarvis P.
FEBS Lett. 544:79-85(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, MUTAGENESIS OF GLU-208; ASP-217; ASP-219 AND GLU-220.
[11]"Dimerization of Toc-GTPases at the chloroplast protein import machinery."
Weibel P., Hiltbrunner A., Brand L., Kessler F.
J. Biol. Chem. 278:37321-37329(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, DIMERIZATION WITH TOC159, MUTAGENESIS OF ARG-130.
[12]"The roles of Toc34 and Toc75 in targeting the Toc159 preprotein receptor to chloroplasts."
Wallas T.R., Smith M.D., Sanchez-Nieto S., Schnell D.J.
J. Biol. Chem. 278:44289-44297(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, SUBCELLULAR LOCATION, MUTAGENESIS OF 45-GLY--SER-50, INTERACTION WITH TOC159.
[13]"Proteomic study of the Arabidopsis thaliana chloroplastic envelope membrane utilizing alternatives to traditional two-dimensional electrophoresis."
Froehlich J.E., Wilkerson C.G., Ray W.K., McAndrew R.S., Osteryoung K.W., Gage D.A., Phinney B.S.
J. Proteome Res. 2:413-425(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: SUBCELLULAR LOCATION, IDENTIFICATION BY MASS SPECTROMETRY.
[14]"The Arabidopsis ppi1 mutant is specifically defective in the expression, chloroplast import, and accumulation of photosynthetic proteins."
Kubis S., Baldwin A., Patel R., Razzaq A., Dupree P., Lilley K., Kurth J., Leister D., Jarvis P.
Plant Cell 15:1859-1871(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, DISRUPTION PHENOTYPE, TISSUE SPECIFICITY, INDUCTION BY LIGHT, DEVELOPMENTAL STAGE.
[15]"Proteomics of the chloroplast envelope membranes from Arabidopsis thaliana."
Ferro M., Salvi D., Brugiere S., Miras S., Kowalski S., Louwagie M., Garin J., Joyard J., Rolland N.
Mol. Cell. Proteomics 2:325-345(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: SUBCELLULAR LOCATION, IDENTIFICATION BY MASS SPECTROMETRY.
Strain: cv. Wassilewskija.
[16]"An outer envelope membrane component of the plastid protein import apparatus plays an essential role in Arabidopsis."
Constan D., Patel R., Keegstra K., Jarvis P.
Plant J. 38:93-106(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[17]"A role of Toc33 in the protochlorophyllide-dependent plastid import pathway of NADPH:protochlorophyllide oxidoreductase (POR) A."
Reinbothe S., Pollmann S., Springer A., James R.J., Tichtinsky G., Reinbothe C.
Plant J. 42:1-12(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: INTERACTION WITH PPORA AND OP161.
[18]"In vivo assessment of the significance of phosphorylation of the Arabidopsis chloroplast protein import receptor, atToc33."
Aronsson H., Combe J., Patel R., Jarvis P.
FEBS Lett. 580:649-655(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, PHOSPHORYLATION AT SER-181, MUTAGENESIS OF SER-181.
[19]"Deletion of core components of the plastid protein import machinery causes differential arrest of embryo development in Arabidopsis thaliana."
Hust B., Gutensohn M.
Plant Biol. 8:18-30(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[20]"Phospho-mimicry mutant of atToc33 affects early development of Arabidopsis thaliana."
Oreb M., Zoryan M., Vojta A., Maier U.G., Eichacker L.A., Schleiff E.
FEBS Lett. 581:5945-5951(2007) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, PHOSPHORYLATION AT SER-181.
[21]"In vitro comparative kinetic analysis of the chloroplast Toc GTPases."
Reddick L.E., Vaughn M.D., Wright S.J., Campbell I.M., Bruce B.D.
J. Biol. Chem. 282:11410-11426(2007) [PubMed] [Europe PMC] [Abstract]
Cited for: BIOPHYSICOCHEMICAL PROPERTIES.
[22]"Dimerization is important for the GTPase activity of chloroplast translocon components atToc33 and psToc159."
Yeh Y.-H., Kesavulu M.M., Li H.-M., Wu S.-Z., Sun Y.-J., Konozy E.H.E., Hsiao C.-D.
J. Biol. Chem. 282:13845-13853(2007) [PubMed] [Europe PMC] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (3.2 ANGSTROMS) OF 2-250 IN COMPLEX WITH GDP AND MAGNESIUM, DIMERIZATION, MUTAGENESIS OF ARG-130.
[23]"On the significance of Toc-GTPase homodimers."
Koenig P., Oreb M., Rippe K., Muhle-Goll C., Sinning I., Schleiff E., Tews I.
J. Biol. Chem. 283:23104-23112(2008) [PubMed] [Europe PMC] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (1.96 ANGSTROMS) OF 1-251 IN COMPLEX WITH GDP AND MAGNESIUM, DIMERIZATION, MUTAGENESIS OF ARG-130.
[24]"The GTPase cycle of the chloroplast import receptors Toc33/Toc34: implications from monomeric and dimeric structures."
Koenig P., Oreb M., Hoefle A., Kaltofen S., Rippe K., Sinning I., Schleiff E., Tews I.
Structure 16:585-596(2008) [PubMed] [Europe PMC] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (2.85 ANGSTROMS) OF 1-251 IN COMPLEX WITH GDP; GNP AND MAGNESIUM, DIMERIZATION.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AJ010724 mRNA. Translation: CAC17698.1.
U89959 Genomic DNA. Translation: AAC24375.1.
CP002684 Genomic DNA. Translation: AEE27409.1.
CP002684 Genomic DNA. Translation: AEE27410.1.
AY042869 mRNA. Translation: AAK68809.1.
AY056448 mRNA. Translation: AAL08304.1.
BT025654 mRNA. Translation: ABF74715.1.
RefSeqNP_001117215.1. NM_001123743.1.
NP_171730.1. NM_100108.4.
UniGeneAt.10710.
At.70625.

3D structure databases

PDBe
RCSB PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
2J3EX-ray3.20A2-250[»]
3BB3X-ray2.94A1-251[»]
3BB4X-ray2.85A1-251[»]
3DEFX-ray1.96A1-251[»]
ProteinModelPortalO23680.
SMRO23680. Positions 2-250.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

BioGrid24483. 8 interactions.
IntActO23680. 8 interactions.

Proteomic databases

PaxDbO23680.
PRIDEO23680.

Protocols and materials databases

DNASU839248.
StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblPlantsAT1G02280.1; AT1G02280.1; AT1G02280.
AT1G02280.2; AT1G02280.2; AT1G02280.
GeneID839248.
KEGGath:AT1G02280.

Organism-specific databases

TAIRAT1G02280.

Phylogenomic databases

eggNOGNOG82276.
HOGENOMHOG000264764.
InParanoidO23680.
OMAIRAGSKM.
PhylomeDBO23680.
ProtClustDBCLSN2914637.

Enzyme and pathway databases

BioCycARA:AT1G02280-MONOMER.

Gene expression databases

ArrayExpressO23680.
GenevestigatorO23680.

Family and domain databases

Gene3D3.40.50.300. 1 hit.
InterProIPR006703. AIG1.
IPR027417. P-loop_NTPase.
IPR005688. Toc34.
[Graphical view]
PfamPF04548. AIG1. 1 hit.
[Graphical view]
PIRSFPIRSF038134. Toc34. 1 hit.
SUPFAMSSF52540. SSF52540. 1 hit.
TIGRFAMsTIGR00991. 3a0901s02IAP34. 1 hit.
ProtoNetSearch...

Other

EvolutionaryTraceO23680.

Entry information

Entry nameTOC33_ARATH
AccessionPrimary (citable) accession number: O23680
Secondary accession number(s): Q94B42, Q9GDD3
Entry history
Integrated into UniProtKB/Swiss-Prot: October 14, 2008
Last sequence update: January 1, 1998
Last modified: April 16, 2014
This is version 97 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programPlant Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

Arabidopsis thaliana

Arabidopsis thaliana: entries and gene names