Differential and Additive Effects of the Three Conserved Isoleucine Residues in the Promoter -10 Binding Region on Bacillus subtilis .SIGMA.A Structure and Function.

スポンサーリンク

概要

• 論文の詳細を見る

• The promoter -10 binding region of the Bacillus subtilis δA factor forms an amphiphilic α-helix with three conserved isoleucines located at four-residue intervals. To investigate the structural and functional roles of the three isoleucine residues, we constructed a series of sigA mutants with single and double Ile-to-Ala substitutions on the hydrophobic face of this α-helix and isolated intragenic revertants with either same-site or second-site suppressor that partially restores the structural stability and transcription activity of the mutant δA factors. Our data show that the three conserved isoleucine residues (Ile-194, Ile-198, and Ile-202) are involved in the hydrophobic core packing of δA; they affect differentially and additively the structure and function of δA, with the central isoleucine residue (Ile-198) playing the most important role. By analogy with the crystal structure of a δ70 peptide, it is apparent that interdigital interactions exist between the three conserved isoleucine residues and certain hydrophobic amino acids in region 2.1 of δA. They include at least the van der Waals contacts between Ile-194 and both Leu-145 and Ile-149, between Ile-198 and both Ile-149 and Tyr-153, as well as between Ile-202 and Tyr-153. The same-site suppressors, Val-194 and Val-198, restore the structural stability and transcription activity of δA by repacking the hydrophobic core of δA. The second-site suppressor (S291F) appears to be allele-specific, but it is not as effective as the same-site suppressors in restoring δA structure and function.

• 社団法人 日本生化学会の論文

著者

• Chang Ban-yang

  Institute Of Biochemistry National Chung-hsing University

• Wang Wen-horng

  Institute Of Biochemistry National Chung-hsing University

• LIAO Chao-tsai

  Institute of Biochemistry, National Chung-Hsing University

• Yang Hou-shan

  Institute Of Biochemistry National Chung-hsing University

• Chen Jia-perng

  Institute Of Biochemistry National Chung-hsing University

関連論文

• The Importance of a Proper Helical Structure in the Promoter -10 Binding Region to Bacillus subtilis σ^A Structure and Function
• The importance of Region 2.1 in Sustaining the Functional Structure of the Bacillus subtilis σ^A Factor
• Differential and Additive Effects of the Three Conserved Isoleucine Residues in the Promoter-10 Binding Region on Bacillus subtilis σ^A Structure and Function
• Differential and Additive Effects of the Three Conserved Isoleucine Residues in the Promoter -10 Binding Region on Bacillus subtilis .SIGMA.A Structure and Function.

スポンサーリンク