1aqn
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Translational initiation factor 3 (IF3) is an RNA helix destabilizing | + | Translational initiation factor 3 (IF3) is an RNA helix destabilizing protein which interacts with strongly conserved sequences in 16S rRNA, one at the 3' terminus and one in the central domain. It was therefore of interest to identify particular residues whose exposure changes upon IF3 binding. Chemical and enzymatic probing of central domain nucleotides of 16S rRNA in 30S ribosomal subunits was carried out in the presence and absence of IF3. Bases were probed with dimethyl sulfate (DMS), at A(N-1), C(N-3), and G(N-7), and with N-cyclohexyl-N'-[2-(N-methyl-4-morpholinio)ethyl] carbodiimide p-toluenesulfonate (CMCT), at G(N-1) and U(N-3). RNase T1 and nuclease S1 were used to probe unpaired nucleotides, and RNase V1 was used to monitor base-paired or stacked nucleotides. 30S subunits in physiological buffers were probed in the presence and absence of IF3. The sites of cleavage and modification were detected by primer extension. IF3 binding to 30S subunits was found to reduce the chemical reactivity and enzymatic accessibility of some sites and to enhance attack at other sites in the conserved central domain of 16S rRNA, residues 690-850. IF3 decreased CMCT attack at U701 and U793 and V1 attack at G722, G737, and C764; IF3 enhanced DMS attack at A814 and V1 attack at U697, G833, G847, and G849. Many of these central domain sites are strongly conserved and with the conserved 3'-terminal site define a binding domain for IF3 which correlates with a predicted cleft in two independent models of the 30S ribosomal subunit. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Subtilisin]] | [[Category: Subtilisin]] | ||
| - | [[Category: Howard, A | + | [[Category: Howard, A J.]] |
[[Category: Whitlow, M.]] | [[Category: Whitlow, M.]] | ||
| - | [[Category: Wood, J | + | [[Category: Wood, J F.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: IPA]] | [[Category: IPA]] | ||
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[[Category: serine proteinase]] | [[Category: serine proteinase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:47:22 2008'' |
Revision as of 09:47, 21 February 2008
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SUBTILISIN MUTANT 8324
Overview
Translational initiation factor 3 (IF3) is an RNA helix destabilizing protein which interacts with strongly conserved sequences in 16S rRNA, one at the 3' terminus and one in the central domain. It was therefore of interest to identify particular residues whose exposure changes upon IF3 binding. Chemical and enzymatic probing of central domain nucleotides of 16S rRNA in 30S ribosomal subunits was carried out in the presence and absence of IF3. Bases were probed with dimethyl sulfate (DMS), at A(N-1), C(N-3), and G(N-7), and with N-cyclohexyl-N'-[2-(N-methyl-4-morpholinio)ethyl] carbodiimide p-toluenesulfonate (CMCT), at G(N-1) and U(N-3). RNase T1 and nuclease S1 were used to probe unpaired nucleotides, and RNase V1 was used to monitor base-paired or stacked nucleotides. 30S subunits in physiological buffers were probed in the presence and absence of IF3. The sites of cleavage and modification were detected by primer extension. IF3 binding to 30S subunits was found to reduce the chemical reactivity and enzymatic accessibility of some sites and to enhance attack at other sites in the conserved central domain of 16S rRNA, residues 690-850. IF3 decreased CMCT attack at U701 and U793 and V1 attack at G722, G737, and C764; IF3 enhanced DMS attack at A814 and V1 attack at U697, G833, G847, and G849. Many of these central domain sites are strongly conserved and with the conserved 3'-terminal site define a binding domain for IF3 which correlates with a predicted cleft in two independent models of the 30S ribosomal subunit.
About this Structure
1AQN is a Single protein structure of sequence from Bacillus amyloliquefaciens with , and as ligands. Active as Subtilisin, with EC number 3.4.21.62 Known structural/functional Sites: , , , , , , , and . Full crystallographic information is available from OCA.
Reference
Escherichia coli initiation factor 3 protein binding to 30S ribosomal subunits alters the accessibility of nucleotides within the conserved central region of 16S rRNA., Muralikrishna P, Wickstrom E, Biochemistry. 1989 Sep 19;28(19):7505-10. PMID:2514787
Page seeded by OCA on Thu Feb 21 11:47:22 2008
Categories: Bacillus amyloliquefaciens | Single protein | Subtilisin | Howard, A J. | Whitlow, M. | Wood, J F. | CA | IPA | UNX | Hydrolase | Serine proteinase
