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Structure prediction of large complexes

Large macromolecular complexes and molecular machines present a particular challenge in structure determination. Generally too large to be crystallized, and too complex to solve by NMR, determining the structure of these objects usually requires the combination of high-resolution microscopy combined with computational refinement and analysis. The main techniques used are cryo-electron microscopy (Cryo-EM) and standard light microscopy.

Protein structure repositories

Most of the protein structures discovered to date can be found in a large protein repository called the RCSB Protein DataBank (PDB) . The Protein Data Bank (PDB) is a public domain repository that contains experimentally determined structures of three-dimensionalproteins. The majority of the proteins in the PDB have been determined by x-ray crystallography, but the number of proteins determined using NMRmethods has been increasing as efficient computational techniques to derive structures from NMR data have been developed. A few electron diffraction structures are also available. The PDB was originally established at Brookhaven National Laboratory in October, 1971, with 7structures. Currently, the database is maintained by Rutgers University, the State University of New Jersey, the San DiegoSupercomputer Center at the University of California, San Diego, and the National Institute of Standards and Technology. The current number of proteins (and/or nucleic acids) in the PDB database is displayed at the top-right corner of the main PDB page. The imaging method statistics of these structures (i.e., which methods were used for what fraction of the structures), as well as other classifications, can be found here . The European Bioinformatics Institute Macromolecular Structure Database group (UK) and the Institute forProtein Research at Osaka University (Japan) are international contributors to the contents of the PDB.

Visualizing protein structures

A few molecular visualization programs

  • Visual Molecular Dynamics (VMD) was originally developed for viewing molecular simulation trajectories. It is a very powerful, full-featured, and customizable molecular viewing package. Customization is available using Tcl/Tk scripting. Information on Tcl/Tk scripting can be found at this Tcl/Tk website.
  • PyMol is an open-source molecular viewer that can be used to generate professional-looking images. PyMol is highly customizable through the Python scripting language.
  • Protein Explorer is an easy-to-use, web browser-based visualization tool. Protein explorer is built using the MDL Chime browser plugin, which in turn is based on the RasMol viewer. Because Chime only works under Windows and Macintosh OS, the use of Protein Explorer is restricted to those platforms.
  • JMol is a Java-based molecular viewer. In applet form, it can be downloaded on-the-fly to view structures from the web. A stand-alone version also exists, which can be used independently of a web browser.
  • Chimera is a powerful visualizer and analysis tool that can be comfortably used with very large molecular complexes. It can also produce very high-quality images for use in presentations and publications.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Geometric methods in structural computational biology. OpenStax CNX. Jun 11, 2007 Download for free at http://cnx.org/content/col10344/1.6
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