1
|
Sora V, Tiberti M, Beltrame L, Dogan D, Robbani SM, Rubin J, Papaleo E. PyInteraph2 and PyInKnife2 to Analyze Networks in Protein Structural Ensembles. J Chem Inf Model 2023; 63:4237-4245. [PMID: 37437128 DOI: 10.1021/acs.jcim.3c00574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Due to the complex nature of noncovalent interactions and their long-range effects, analyzing protein conformations using network theory can be enlightening. Protein Structure Networks (PSNs) provide a convenient formalism to study protein structures in relation to essential properties such as key residues for structural stability, allosteric communication, and the effects of modifications of the protein. PSNs can be defined according to very different principles, and the available tools have limitations in input formats, supported models, and version control. Other outstanding problems are related to the definition of network cutoffs and the assessment of the stability of the network properties. The protein science community could benefit from a common framework to carry out these analyses and make them easier to reproduce, reuse, and evaluate. We here provide two open-source software packages, PyInteraph2 and PyInKnife2, to implement and analyze PSNs in a reproducible and documented manner. PyInteraph2 interfaces with multiple formats for protein ensembles and incorporates different network models with the possibility of integrating them into a macronetwork and performing various downstream analyses, including hubs, connected components, and several other centrality measures, and visualizes the networks or further analyzes them thanks to compatibility with Cytoscape.PyInKnife2 that supports the network models implemented in PyInteraph2. It employs a jackknife resampling approach to estimate the convergence of network properties and streamline the selection of distance cutoffs. We foresee that the modular structure of the code and the supported version control system will promote the transition to a community-driven effort, boost reproducibility, and establish common protocols in the PSN field. As developers, we will guarantee the introduction of new functionalities and maintenance, assistance, and training of new contributors.
Collapse
Affiliation(s)
- Valentina Sora
- Cancer Structural Biology, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark
- Cancer Systems Biology, Section of Bioinformatics, Department of Health and Technology, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Matteo Tiberti
- Cancer Structural Biology, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Ludovica Beltrame
- Cancer Systems Biology, Section of Bioinformatics, Department of Health and Technology, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Deniz Dogan
- Cancer Structural Biology, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Shahriyar Mahdi Robbani
- Cancer Structural Biology, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Joshua Rubin
- Cancer Structural Biology, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Elena Papaleo
- Cancer Structural Biology, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark
- Cancer Systems Biology, Section of Bioinformatics, Department of Health and Technology, Technical University of Denmark, 2800 Lyngby, Denmark
| |
Collapse
|
2
|
Progress in understanding the structural mechanism underlying prestin's electromotile activity. Hear Res 2021; 423:108423. [PMID: 34987017 DOI: 10.1016/j.heares.2021.108423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 11/17/2021] [Accepted: 12/22/2021] [Indexed: 11/21/2022]
Abstract
Prestin (SLC26A5), a member of the SLC26 transporter family, is the molecular actuator that drives OHC electromotility (eM). A wealth of biophysical data indicates that eM is mediated by an area motor mechanism, in which prestin molecules act as elementary actuators by changing their area in the membrane in response to changes in membrane potential. The area changes of a large and densely packed population of prestin molecules sum up, resulting in macroscopic cellular movement. At the single protein level, this model implies major voltage-driven conformational rearrangements. However, the nature of these structural dynamics remained unknown. A main obstacle in elucidating the eM mechanism has been the lack of structural information about SLC26 transporters. The recent emergence of several high-resolution cryo-EM structures of prestin as well as other SLC26 transporter family members now provides a reliable picture of prestin's molecular architecture. Thus, SLC26 transporters including prestin generally are dimers, and each protomer is folded according to a 7+7 transmembrane domain inverted repeat (7TMIR) architecture. Here, we review these structural findings and discuss insights into a potential molecular mechanism. Most important, distinct conformations were observed when purifying and imaging prestin bound to either its physiological ligand, chloride, or to competitively inhibitory anions, sulfate or salicylate. Despite differences in detail, these structural snapshots indicate that the conformational landscape of prestin includes rearrangements between the two major domains of prestin's transmembrane region (TMD), core and scaffold ('gate') domains. Notably, distinct conformations differ in the area the TMD occupies in the membrane and in their impact on the immediate lipid environment. Both effects can contribute to generate membrane deformation and thus may underly electromotility. Further functional studies will be necessary to determine whether these or similar structural rearrangements are driven by membrane potential to mediate piezoelectric activity. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.
Collapse
|