Journal: eLife

Article Title: A conserved histidine modulates HSPB5 structure to trigger chaperone activity in response to stress-related acidosis

doi: 10.7554/eLife.07304

Figure Lengend Snippet: ( A ) Backbone traces of ten ACD structures determined by RosettaOligomer are aligned over all residues (RMSD of 1.4 Å). Subunits of the dimer are shown in blue and gray. ( B ) Cartoon representation of one member of the HSPB5-ACD ensemble is shown. The six strands of the β-sandwich structure are labeled using previously defined nomenclature for ACD structures. The dimer is formed by antiparallel arrangement of the β6+7 strands at the interface. Loop 5/6 is highlighted in the blue subunit. ( C ) The sequence of the ACD construct for which the solution structure was solved is shown with elements of secondary structure highlighted. ( D ) The alignment of the β6+7 strands at the dimer interface, shown schematically, places Glu-117 across from Glu-117′. This alignment is called ‘APII’ in previous reports . ( E ) Overlay of protomers from all available HSPB5-ACD structures. All members of the solution NMR structure (this paper; PDB 2N0K) and the solid-state NMR structure (2KLR; ) are shown in dark gray and light gray, respectively. Five crystal structures are shown: (1) 2WJ7 (yellow), (2) 3L1G (orange), (3) 4M5S (green), (4) 4M5T (red), and (5) 2Y22 (blue). DOI: http://dx.doi.org/10.7554/eLife.07304.003 10.7554/eLife.07304.004 Figure 1—source data 1. Comparison of the NMR solution structure and published structures. Backbone root mean square deviations (rmsd) between the solution structure and published structures and the correlation between experimentally measured residual dipolar coupling (RDC) values and those calculated for each published structure (PALES Correlation Coefficient) are given. Values in parentheses are calculated without including loop regions between the β-strands. Protomer–protomer and dimer–dimer rmsd between 2KLR and solution structure ensembles are the averages between all pairwise combinations of all structures in each ensemble. Rmsd values between the solution structure ensemble and the crystal structures are the average of all pairwise rmsd between the ten structures in the ensemble and the crystal structure. 2KLR: solid-state NMR structure; 2WJ7:crystal structure at pH 9.0; 3L1G:crystal structure at pH 4.6; 4M5S: crystal structure at pH 6.0. DOI: http://dx.doi.org/10.7554/eLife.07304.004 10.7554/eLife.07304.005 Figure 1—source data 2. Multiple sequence alignment of the ten human sHSPs. ClustalOmega was used to align the sequences. Structural features of HSPB5-ACD are highlighted as follows: ACD is denoted by the blue line; His-104 is identified by the blue arrow; Loop 5/6 is shown in red box; dimer interface is shown in green box. All ACD histidine residues are shown in bold font. DOI: http://dx.doi.org/10.7554/eLife.07304.005

Article Snippet: Ten models with the lowest Rosetta full-atom energy in the best-ranked cluster were selected as the final structural ensemble and deposited in the Protein Databank as PDB 2N0K.

Techniques: Labeling, Sequencing, Construct, Comparison

Journal: eLife

Article Title: A conserved histidine modulates HSPB5 structure to trigger chaperone activity in response to stress-related acidosis

doi: 10.7554/eLife.07304

Figure Lengend Snippet: Top panel: ten individual members of the solution ensemble are shown. One protomer of the dimer is in cyan; the other protomer is in gray. His-104 is shown as space-filling spheres; carbonyl groups that are in proximity to His-104 are shown in stick representation; side chains that are proximal to His-104 are shown in stick representation; side chains in Loop 5/6 and in the dimer interface as shown as lines; Bottom panel: examples of a loop-up (shown in cyan; this publication PDB 2N0K) and loop-down conformation (shown in violet; from 2KLR) are shown to illustrate the rearrangement of potential interacting partners in the two conformations. As above, the second subunit in a dimer is shown in gray. DOI: http://dx.doi.org/10.7554/eLife.07304.006

Article Snippet: Ten models with the lowest Rosetta full-atom energy in the best-ranked cluster were selected as the final structural ensemble and deposited in the Protein Databank as PDB 2N0K.

Techniques: