Role of carboxy-terminal region in proofreading function of methionyl-tRNA synthetase in Escherichia coli

Tubulins contain a glycine-rich loop, that has been implicated in microtubule dynamics by means of an intramolecular interaction with the carboxy-terminal region. As a further extension of the analysis of the role of the carboxy-terminal region in tubulin folding we have mutated the glycine-rich loop of tubulin subunits. An alpha-tubulin point mutant with a T150-->G substitution (the corresponding residue present in beta-tubulin) was able to incorporate into dimers and microtubules. On the other hand, four beta-tubulin point mutants, including the G148-->T substitution, did not incorporate into dimers, did not release monomers, but were able to form C900 and C300 complexes (intermediates in the process of tubulin folding). Three other mutants within this region (which approximately encompasses residues 137–152) were incapable of forming dimers and C300 complexes but gave rise to the formation of C900 complexes. These results suggest that tubulin goes through two sequential folding states during the folding process, first in association with TCP1-complexes (C900) prior to the transfer to C300 complexes. It is this second step that implies binding/hydrolysis of GTP, reinforcing our previous proposed model for tubulin folding and assembly.

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Carboxy-Terminal Region Involved in Activity of Escherichia coli TolC

Journal of Bacteriology ◽

10.1128/jb.183.23.6961-6964.2001 ◽

2001 ◽

Vol 183 (23) ◽

pp. 6961-6964 ◽

Cited By ~ 18

Author(s):

Hiroyasu Yamanaka ◽

Hiroshi Izawa ◽

Keinosuke Okamoto

Keyword(s):

Escherichia Coli ◽

Amino Acid ◽

Outer Membrane ◽

Amino Acid Residue ◽

Terminal Region ◽

Transport Activity ◽

Carboxy Terminus ◽

Partial Deletion ◽

Carboxy Terminal Region ◽

Carboxy Terminal

ABSTRACT The Escherichia coli TolC acts as a channel tunnel in the transport of various molecules across the outer membrane. Partial-deletion studies of tolC revealed that the region extending from the 50th to the 60th amino acid residue from the carboxy terminus plays an important role in this transport activity of TolC.

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Critical Role of the Acceptor Stem of tRNAsMet in their Aminoacylation by Escherichia coli Methionyl-tRNA Synthetase

Journal of Molecular Biology ◽

10.1006/jmbi.1993.1005 ◽

1993 ◽

Vol 229 (1) ◽

pp. 26-36 ◽

Cited By ~ 29

Author(s):

Thierry Meinnel ◽

Yves Mechulam ◽

Christine Lazennec ◽

Sylvain Blanquet ◽

Guy Fayat

Keyword(s):

Escherichia Coli ◽

Critical Role ◽

Trna Synthetase ◽

Acceptor Stem ◽

Methionyl Trna Synthetase

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Stability of the Escherichia coli Division Inhibitor Protein MinC Requires Determinants in the Carboxy-Terminal Region of the Protein

Journal of Bacteriology ◽

10.1128/jb.180.1.175-177.1998 ◽

1998 ◽

Vol 180 (1) ◽

pp. 175-177 ◽

Cited By ~ 8

Author(s):

Mita Sen ◽

Lawrence I. Rothfield

Keyword(s):

Escherichia Coli ◽

Terminal Region ◽

Lon Protease ◽

Inhibitor Protein ◽

Loss Of Function ◽

Cellular Concentration ◽

Carboxy Terminal Region ◽

The Stability ◽

Carboxy Terminal

ABSTRACT Certain mutations in the C-terminal region of the Escherichia coli division inhibitor protein MinC cause loss of function of the division inhibitor by making MinC more sensitive to degradation by Lon protease, implying a possible role for the C-terminal region in regulating the stability and cellular concentration of MinC.

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