COMPARATIVE STUDIES OF STRUCTURE AND FUNCTION OF DNA-DEPENDENT RNA POLYMERASES FROM EUBACTERIA AND ARCHAEBACTERIA

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 of carbonic anhydrase: comparative studies of sulphonamide binding to human erythrocyte carbonic anhydrases B and C

Drug Action at the Molecular Level ◽

10.1007/978-1-349-03230-3_4 ◽

1977 ◽

pp. 73-91 ◽

Cited By ~ 24

Author(s):

K. K. Kannan ◽

I. Vaara ◽

B. Notstrand ◽

S. Lövgren ◽

A. Boren ◽

...

Keyword(s):

Carbonic Anhydrase ◽

Human Erythrocyte ◽

Comparative Studies ◽

Structure And Function ◽

Carbonic Anhydrases ◽

And Function

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Structure and Function of RNA Polymerases and the Transcription Machineries

Subcellular Biochemistry - Macromolecular Protein Complexes ◽

10.1007/978-3-319-46503-6_9 ◽

2017 ◽

pp. 225-270 ◽

Cited By ~ 9

Author(s):

Joachim Griesenbeck ◽

Herbert Tschochner ◽

Dina Grohmann

Keyword(s):

Structure And Function ◽

Rna Polymerases ◽

And Function

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Comparative structure and function of marsupial spermatozoa

Reproduction Fertility and Development ◽

10.1071/rd9940421 ◽

1994 ◽

Vol 6 (4) ◽

pp. 421 ◽

Cited By ~ 20

Author(s):

PD Temple-Smith

Keyword(s):

Sperm Motility ◽

Comparative Studies ◽

Current Knowledge ◽

Structure And Function ◽

Basic Organization ◽

Nuclear Shaping ◽

Comparative Structure ◽

Nuclear Rotation ◽

And Function ◽

Posterior Ring

Marsupial sperm structure has been the focus of many comparative studies in the last 30 years. Although the basic organization of the marsupial spermatozoon is similar to that of eutherian mammals, spermatozoa from this branch of therian evolution have developed a specific suite of characters which clearly distinguish them from the Eutheria. This review surveys these specializations and examines current knowledge on their respective functions and the forces which shaped their evolution. Nuclear shaping and stability, the asymmetric positioning of the acrosome, and the unusual neck articulation are discussed. Although recent observations have provided evidence of a marsupial equatorial segment and posterior ring, the marsupial equivalent of the eutherian postacrosomal sheath has not been identified. The unusual neck structure of marsupial spermatozoa and the mobile articulation of the connecting piece are discussed in relation to nuclear rotation and the events associated with this process. Increasing flagellar length in some species is associated with extremes in flagellar organization and its effect on sperm motility is discussed.

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