PDBsum entry 1zu2

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protein links
Transport protein PDB id
Jmol PyMol
Protein chain
158 a.a. *
* Residue conservation analysis
PDB id:
Name: Transport protein
Title: Solution nmr structure of the plant tom20 mitochondrial import receptor from arabidopsis thaliana
Structure: Mitochondrial import receptor subunit tom20-3. Chain: a. Fragment: isoform-3 cytosolic receptor domain. Synonym: translocase of outer membrane 20 kda isoform 3. Engineered: yes
Source: Arabidopsis thaliana. Thale cress. Organism_taxid: 3702. Gene: tom20-3. Expressed in: escherichia coli. Expression_system_taxid: 562.
NMR struc: 20 models
Authors: A.J.Perry,J.M.Hulett,T.Lithgow,P.R.Gooley
Key ref:
A.J.Perry et al. (2006). Convergent evolution of receptors for protein import into mitochondria. Curr Biol, 16, 221-229. PubMed id: 16461275 DOI: 10.1016/j.cub.2005.12.034
30-May-05     Release date:   06-Dec-05    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P82874  (TO203_ARATH) -  Mitochondrial import receptor subunit TOM20-3
202 a.a.
158 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 8 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     mitochondrial outer membrane translocase complex   1 term 
  Biological process     protein import into mitochondrial outer membrane   1 term 


DOI no: 10.1016/j.cub.2005.12.034 Curr Biol 16:221-229 (2006)
PubMed id: 16461275  
Convergent evolution of receptors for protein import into mitochondria.
A.J.Perry, J.M.Hulett, V.A.Likić, T.Lithgow, P.R.Gooley.
BACKGROUND: Mitochondria evolved from intracellular bacterial symbionts. Establishing mitochondria as organelles required a molecular machine to import proteins across the mitochondrial outer membrane. This machinery, the TOM complex, is composed of at least seven component parts, and its creation and evolution represented a sizeable challenge. Although there is good evidence that a core TOM complex, composed of three subunits, was established in the protomitochondria, we suggest that the receptor component of the TOM complex arose later in the evolution of this machine. RESULTS: We have solved by nuclear magnetic resonance the structure of the presequence binding receptor from the TOM complex of the plant Arabidopsis thaliana. The protein fold suggests that this protein, AtTom20, belongs to the tetratricopeptide repeat (TPR) superfamily, but it is unusual in that it contains insertions lengthening the helices of each TPR motif. Peptide titrations map the presequence binding site to a groove of the concave surface of the receptor. In vitro functional assays and peptide titrations suggest that the plant Tom20 is functionally equivalent to fungal and animal Tom20s. CONCLUSIONS: Comparison of the sequence and structure of Tom20 from plants and animals suggests that these two presequence binding receptors evolved from two distinct ancestral genes following the split of the animal and plant lineages. The need to bind equivalent mitochondrial targeting sequences and to make similar interactions within an equivalent protein translocation machine has driven the convergent evolution of two distinct proteins to a common structure and function.
  Selected figure(s)  
Figure 2.
Figure 2. Structure of AtTom20
Figure 3.
Figure 3. Structural Comparison of Plant and Animal Tom20 Proteins
  The above figures are reprinted by permission from Cell Press: Curr Biol (2006, 16, 221-229) copyright 2006.  
  Figures were selected by the author.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21376056 J.C.Danne, and R.F.Waller (2011).
Analysis of Dinoflagellate Mitochondrial Protein Sorting Signals Indicates a Highly Stable Protein Targeting System across Eukaryotic Diversity.
  J Mol Biol, 408, 643-653.  
21080492 R.Szklarczyk, and M.A.Huynen (2010).
Mosaic origin of the mitochondrial proteome.
  Proteomics, 10, 4012-4024.  
20124346 T.Lithgow, and A.Schneider (2010).
Evolution of macromolecular import pathways in mitochondria, hydrogenosomes and mitosomes.
  Philos Trans R Soc Lond B Biol Sci, 365, 799-817.  
19995731 A.K.Berglund, E.Spånning, H.Biverståhl, G.Maddalo, C.Tellgren-Roth, L.Mäler, and E.Glaser (2009).
Dual Targeting to Mitochondria and Chloroplasts: Characterization of Thr-tRNA Synthetase Targeting Peptide.
  Mol Plant, 2, 1298-1309.  
19083240 A.M.Duchêne, C.Pujol, and L.Maréchal-Drouard (2009).
Import of tRNAs and aminoacyl-tRNA synthetases into mitochondria.
  Curr Genet, 55, 1.  
19187233 C.Carrie, E.Giraud, and J.Whelan (2009).
Protein transport in organelles: Dual targeting of proteins to mitochondria and chloroplasts.
  FEBS J, 276, 1187-1195.  
19531743 M.J.Dagley, P.Dolezal, V.A.Likic, O.Smid, A.W.Purcell, S.K.Buchanan, J.Tachezy, and T.Lithgow (2009).
The protein import channel in the outer mitosomal membrane of Giardia intestinalis.
  Mol Biol Evol, 26, 1941-1947.  
18635686 J.Catusse, J.M.Strub, C.Job, A.Van Dorsselaer, and D.Job (2008).
Proteome-wide characterization of sugarbeet seed vigor and its tissue specific expression.
  Proc Natl Acad Sci U S A, 105, 10262-10267.  
18465197 R.V.Sternberg (2008).
DNA codes and information: formal structures and relational causes.
  Acta Biotheor, 56, 205-232.  
18811953 Y.T.Hwang, A.W.McCartney, S.K.Gidda, and R.T.Mullen (2008).
Localization of the Carnation Italian ringspot virus replication protein p36 to the mitochondrial outer membrane is mediated by an internal targeting signal and the TOM complex.
  BMC Cell Biol, 9, 54.  
17825565 M.J.Baker, A.E.Frazier, J.M.Gulbis, and M.T.Ryan (2007).
Mitochondrial protein-import machinery: correlating structure with function.
  Trends Cell Biol, 17, 456-464.  
17329106 N.C.Elde, M.Long, and A.P.Turkewitz (2007).
A role for convergent evolution in the secretory life of cells.
  Trends Cell Biol, 17, 157-164.  
17932292 S.S.Merchant, S.E.Prochnik, O.Vallon, E.H.Harris, S.J.Karpowicz, G.B.Witman, A.Terry, A.Salamov, L.K.Fritz-Laylin, L.Maréchal-Drouard, W.F.Marshall, L.H.Qu, D.R.Nelson, A.A.Sanderfoot, M.H.Spalding, V.V.Kapitonov, Q.Ren, P.Ferris, E.Lindquist, H.Shapiro, S.M.Lucas, J.Grimwood, J.Schmutz, P.Cardol, H.Cerutti, G.Chanfreau, C.L.Chen, V.Cognat, M.T.Croft, R.Dent, S.Dutcher, E.Fernández, H.Fukuzawa, D.González-Ballester, D.González-Halphen, A.Hallmann, M.Hanikenne, M.Hippler, W.Inwood, K.Jabbari, M.Kalanon, R.Kuras, P.A.Lefebvre, S.D.Lemaire, A.V.Lobanov, M.Lohr, A.Manuell, I.Meier, L.Mets, M.Mittag, T.Mittelmeier, J.V.Moroney, J.Moseley, C.Napoli, A.M.Nedelcu, K.Niyogi, S.V.Novoselov, I.T.Paulsen, G.Pazour, S.Purton, J.P.Ral, D.M.Riaño-Pachón, W.Riekhof, L.Rymarquis, M.Schroda, D.Stern, J.Umen, R.Willows, N.Wilson, S.L.Zimmer, J.Allmer, J.Balk, K.Bisova, C.J.Chen, M.Elias, K.Gendler, C.Hauser, M.R.Lamb, H.Ledford, J.C.Long, J.Minagawa, M.D.Page, J.Pan, W.Pootakham, S.Roje, A.Rose, E.Stahlberg, A.M.Terauchi, P.Yang, S.Ball, C.Bowler, C.L.Dieckmann, V.N.Gladyshev, P.Green, R.Jorgensen, S.Mayfield, B.Mueller-Roeber, S.Rajamani, R.T.Sayre, and P.Brokstein (2007).
The Chlamydomonas genome reveals the evolution of key animal and plant functions.
  Science, 318, 245-250.  
17948058 T.Saitoh, M.Igura, T.Obita, T.Ose, R.Kojima, K.Maenaka, T.Endo, and D.Kohda (2007).
Tom20 recognizes mitochondrial presequences through dynamic equilibrium among multiple bound states.
  EMBO J, 26, 4777-4787.
PDB codes: 2v1s 2v1t
17008120 A.H.Millar, J.Whelan, and I.Small (2006).
Recent surprises in protein targeting to mitochondria and plastids.
  Curr Opin Plant Biol, 9, 610-615.  
16857931 P.Dolezal, V.Likic, J.Tachezy, and T.Lithgow (2006).
Evolution of the molecular machines for protein import into mitochondria.
  Science, 313, 314-318.  
17099692 R.Albrecht, P.Rehling, A.Chacinska, J.Brix, S.A.Cadamuro, R.Volkmer, B.Guiard, N.Pfanner, and K.Zeth (2006).
The Tim21 binding domain connects the preprotein translocases of both mitochondrial membranes.
  EMBO Rep, 7, 1233-1238.
PDB code: 2ciu
16546069 R.Lister, and J.Whelan (2006).
Mitochondrial protein import: convergent solutions for receptor structure.
  Curr Biol, 16, R197-R199.  
16803880 S.R.Bushell, S.P.Bottomley, J.Rossjohn, and T.Beddoe (2006).
Tracking the unfolding pathway of a multirepeat protein via tryptophan scanning: evidence of localized instability in the mitochondrial import receptor Tom70.
  J Biol Chem, 281, 24345-24350.  
16822756 T.Cavalier-Smith (2006).
Origin of mitochondria by intracellular enslavement of a photosynthetic purple bacterium.
  Proc Biol Sci, 273, 1943-1952.  
17105808 T.Salinas, A.M.Duchêne, L.Delage, S.Nilsson, E.Glaser, M.Zaepfel, and L.Maréchal-Drouard (2006).
The voltage-dependent anion channel, a major component of the tRNA import machinery in plant mitochondria.
  Proc Natl Acad Sci U S A, 103, 18362-18367.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB codes are shown on the right.