Macromolecular Protein Complexes III: Structure and Function

The translocases of the mitochondrial outer and inner membranes, the TOM and TIMs, import hundreds of nucleus-encoded proteins into mitochondria. TOM and TIMs are multi-subunit protein complexes that work in cooperation with other complexes to import proteins in different sub-mitochondrial destinations. The overall architecture of these protein complexes is conserved among yeast/fungi, animals, and plants. Recent studies have revealed unique characteristics of this machinery, particularly in the eukaryotic supergroup Excavata. Despite multiple differences, homologues of Tim17, an essential component of one of the TIM complexes and a member of the Tim17/Tim22/Tim23 family, have been found in all eukaryotes. Here, we review the structure and function of Tim17 and Tim17-containing protein complexes in different eukaryotes, and then compare them to the single homologue of this protein found in Trypanosoma brucei, a unicellular parasitic protozoan.

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Membrane Protein Complexes: Structure and Function

10.1007/978-981-10-7757-9 ◽

2018 ◽

Cited By ~ 1

Keyword(s):

Membrane Protein ◽

Protein Complexes ◽

Structure And Function ◽

Membrane Protein Complexes ◽

And Function

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Structure of the TELO2-TTI1-TTI2 complex and its function in TOR recruitment to the R2TP chaperone

10.1101/2020.11.09.374355 ◽

2020 ◽

Author(s):

Mohinder Pal ◽

Hugo Muñoz-Hernandez ◽

Dennis Bjorklund ◽

Lihong Zhou ◽

Gianluca Degliesposti ◽

...

Keyword(s):

Atpase Activity ◽

Protein Complexes ◽

Kinase Domain ◽

Structure And Function ◽

Pi3 Kinase ◽

Rna Polymerases ◽

Heat Repeat ◽

And Function

AbstractThe R2TP (RUVBL1-RUVBL2-RPAP3-PIH1D1) complex, in collaboration with HSP90, functions as a chaperone for the assembly and stability of protein complexes, including RNA polymerases, snRNPs and PI3 kinase-like kinases (PIKK) such as TOR and SMG1. PIKK stabilisation depends on an additional complex of TELO2, TTI1 and TTI2 (TTT), whose structure and function are poorly understood. We have now determined the cryo-EM structure of the human R2TP-TTT complex that together with biochemical experiments reveals the mechanism of TOR recruitment to the R2TP-TTT chaperone. The HEAT-repeat TTT complex binds the kinase domain of TOR, without blocking its activity, and delivers TOR to the R2TP chaperone. In addition, TTT regulates the R2TP chaperone by inhibiting RUVBL1-RUVBL2 ATPase activity and by modulating the conformation and interactions of the PIH1D1 and RPAP3 components of R2TP. Together, our results show how TTT couples the recruitment of TOR to R2TP with the regulation of this chaperone system.

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Structure and function in organometallic•protein complexes

Journal of Organometallic Chemistry ◽

10.1016/j.jorganchem.2013.07.004 ◽

2014 ◽

Vol 751 ◽

pp. 90-110 ◽

Cited By ~ 19

Author(s):

Richard S. Herrick ◽

Christopher J. Ziegler ◽

Thomas C. Leeper

Keyword(s):

Protein Complexes ◽

Structure And Function ◽

And Function

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Cardiolipin, conformation, and respiratory complex-dependent oligomerization of the major mitochondrial ADP/ATP carrier in yeast

Science Advances ◽

10.1126/sciadv.abb0780 ◽

2020 ◽

Vol 6 (35) ◽

pp. eabb0780 ◽

Cited By ~ 1

Author(s):

N. Senoo ◽

S. Kandasamy ◽

O. B. Ogunbona ◽

M. G. Baile ◽

Y. Lu ◽

...

Keyword(s):

Membrane Proteins ◽

Mitochondrial Membrane ◽

Protein Complexes ◽

Structure And Function ◽

Functional Roles ◽

Respiratory Complex ◽

Respiratory Supercomplexes ◽

Multiple Copies ◽

And Function ◽

Quaternary Assembly

The phospholipid cardiolipin has pleiotropic structural and functional roles that are collectively essential for mitochondrial biology. Yet, the molecular details of how this lipid supports the structure and function of proteins and protein complexes are poorly understood. To address this property of cardiolipin, we use the mitochondrial adenosine 5′-diphosphate/adenosine 5′-triphosphate carrier (Aac) as a model. Here, we have determined that cardiolipin is critical for both the tertiary and quaternary assembly of the major yeast Aac isoform Aac2 as well as its conformation. Notably, these cardiolipin-provided structural roles are separable. In addition, we show that multiple copies of Aac2 engage in shared complexes that are largely dependent on the presence of assembled respiratory complexes III and IV or respiratory supercomplexes. Intriguingly, the assembly state of Aac2 is sensitive to its transport-related conformation. Together, these results expand our understanding of the numerous structural roles provided by cardiolipin for mitochondrial membrane proteins.

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