caa a22 4500 475744284 CHVBK 20180406123508.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1023/A:1007003631120 doi (NATIONALLICENCE)springer-10.1023/A:1007003631120 Probing the Roles of the Only Universally Conserved Leucine Residue (Leu122) in the Oligomerization and Chaperone-like Activity of Mycobacterium tuberculosis Small Heat Shock Protein Hsp16.3 [Elektronische Daten] [Hongzheng Dai, Qilong Mao, Hongmei Yang, Sufang Huang, Zengyi Chang] To understand the role of the only universally conserved hydrophobic residue among all the members of the sHsp family, this extremely well conserved Leu122 residue in Hsp16.3 was replaced by valine, alanine, asparigine, or aspartate residues. Only very small amounts of the L122D and L122N mutant Hsp16.3 proteins were expressed in the transformed E. coli; however, both the L122V and L122A were readily expressed. The L122V and L122A mutant proteins had similar oligomeric structures to the wild-type protein at room temperature. Examination of the L122A mutant protein by native pore gradient PAGE and CD spectroscopy, however, revealed a smaller oligomeric size and different secondary structure at 37°C. Both L122V and L122A mutant proteins exhibited significantly lowered chaperone activities. Observations reported here suggest a very important role of this only universally conserved Leu residue in both the formation of specific oligomeric structures and the molecular chaperone activities of Hsp16.3. Plenum Publishing Corporation, 2000 Small heat shock protein nationallicence molecular chaperone nationallicence α-crystallin domain nationallicence oligomeric structure nationallicence conserved residue nationallicence ANS binding nationallicence Dai Hongzheng State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut Mao Qilong State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut Yang Hongmei State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut Huang Sufang State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut Chang Zengyi State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/4(2000-05-01), 319-326 0277-8033 19:4<319 2000 19 10930 https://doi.org/10.1023/A:1007003631120 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1007003631120 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dai Hongzheng State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut NATIONALLICENCE 700 1- Mao Qilong State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut NATIONALLICENCE 700 1- Yang Hongmei State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut NATIONALLICENCE 700 1- Huang Sufang State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut NATIONALLICENCE 700 1- Chang Zengyi State Key Laboratory of Biomembrane and Membrane Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, 100084, Beijing, China aut NATIONALLICENCE 773 0- Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/4(2000-05-01), 319-326 0277-8033 19:4<319 2000 19 10930 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer