Please wait, while we are loading the content...
| Content Provider | PubMed Central |
|---|---|
| Author | Bennett, Brad Langan, Paul Coates, Leighton Marat, Mustyakimov Schoenborn, Benno Howell, Elizabeth E. Chris, Dealwis |
| Copyright Year | 2006 |
| Abstract | Hydrogen atoms play a central role in many biochemical processes yet are difficult to visualize by x-ray crystallography. Spallation neutron sources provide a new arena for protein crystallography with TOF measurements enhancing data collection efficiency and allowing hydrogen atoms to be located in smaller crystals of larger biological macromolecules. Here we report a 2.2-Å resolution neutron structure of Escherichia coli dihydrofolate reductase (DHFR) in complex with methotrexate (MTX). Neutron data were collected on a 0.3-mm3 D2O-soaked crystal at the Los Alamos Neutron Scattering Center. This study provides an example of using spallation neutrons to study protein dynamics, to identify protonation states directly from nuclear density maps, and to analyze solvent structure. Our structure reveals that the occluded loop conformation [monomer (mon.) A] of the DHFR·MTX complex undergoes greater H/D exchange compared with the closed-loop conformer (mon. B), partly because the Met-20 and β(F-G) loops readily exchange in mon. A. The eight-stranded β sheet of both DHFR molecules resists H/D exchange more than the helices and loops. However, the C-terminal strand, βH, in mon. A is almost fully exchanged. Several D2Os form hydrogen bonds with exchanged amides. At the active site, the N1 atom of MTX is protonated and thus charged when bound to DHFR. Several D2Os are observed at hydrophobic surfaces, including two pockets near the MTX-binding site. A previously unidentified D2O hydrogen bonds with the catalytic D27 in mon. B, stabilizing its negative charge. |
| Related Links | http://dx.doi.org/10.1073/pnas.0604977103 |
| Ending Page | 18498 |
| Page Count | 6 |
| Starting Page | 18493 |
| File Format | |
| ISSN | 00278424 |
| e-ISSN | 10916490 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Issue Number | 49 |
| Volume Number | 103 |
| Language | English |
| Publisher | National Academy of Sciences |
| Publisher Date | 2006-12-05 |
| Access Restriction | Open |
| Rights Holder | National Academy of Sciences |
| Subject Keyword | General Research in Higher Education |
| Content Type | Text |
| Resource Type | Article |
| Subject | Multidisciplinary |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|