HOME >> BIOLOGY >> NEWS
Peering at a machine that pries DNA apart

X-ray crystallography gives scientists new understanding of molecular motor

Boston, MA--October 12, 1999--Harvard researchers have created the first atomic-resolution image of a donut-shaped enzyme, or helicase, that unwinds the DNA double helix to expose its genetic letters for DNA replication. Michael Sawaya, postdoctoral fellow in the lab of Tom Ellenberger, associate professor of biological chemistry and molecular pharmacology (BCMP), worked out the X-ray crystallographic structure reported in the October 15 Cell. The structure is rendered in pictures that show how six individual polypeptide lobes arrange themselves in space to look a bit like a ring of bread buns. It affords researchers the first detailed glance at a family of proteins that remain enigmatic in spite of their recognized status as a fundamental molecular machine of the cell.

"We know next to nothing about how these helicases move on DNA," says Ellenberger. Helicases have become a competitive field of inquiry because defects in human forms underlie several diseases, including the cancer-prone Bloom's syndrome and a disease of premature aging called Werner syndrome. Helicases are interesting for several reasons. First, they are molecular motors, just like myosin, which moves along actin fibrils to contract a muscle, or kinesin, which transports cargo along microtubules. The ring-shaped kind of helicase threads one strand of DNA through its central hole and zips along the double strand at breakneck speed, ploughing through 300 paired nucleotides per second while shoving the second strand out of the way. The enzyme is powerful, too. Other researchers have placed "roadblocks" in the helicase's way by binding proteins on the DNA's back. Yet the helicase knocked these off as it forced its way through.

Second, helicases came in different shapes--some are monomers, others dimers--and they do all sorts of things. The ring-shaped, hexameric helicase studied here spearhea
'"/>

Contact: Peta Gillyatt
gillyatt@hms.harvard.edu
617-432-0443
Harvard Medical School
15-Oct-1999


Page: 1 2 3 4

Related biology news :

1. Peering inside the body, with a new spinliterally
2. Peering inside a blood vessel
3. Israeli scientists reveal the plan of a key cellular machine
4. New understanding of the machinery of flinching
5. RNA could form building blocks for nanomachines
6. Researchers look into components of RNA silencing machinery
7. How DNA repair machinery is a Two-Way Street
8. Mutant biological machine makes proteins but cant let go
9. Powerful machines are coming in small packages
10. Portable kidney dialysis machine developed
11. Purdue biologists expose the inner workings of viral machine

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:10/5/2018)... Ill. (PRWEB) , ... October ... ... Edwardsville, in partnership with the University of Illinois Extension and Monroe County ... Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) Non-Land ...
(Date:10/5/2018)... DIEGO (PRWEB) , ... October 04, 2018 , ... Nothing ... cooking classes have become so popular. , Cooking appeals to companies because ... as group interaction, team cohesion, collaboration and decision-making skills. It’s also appealing in ...
(Date:10/2/2018)... GIBRALTAR, Gilbraltar (PRWEB) , ... October 02, 2018 , ... ... gaps between research, development, and access to stem cell therapy, has launched the pre-sale ... company is building a dual blockchain-based platform that will connect patients and stem cell ...
Breaking Biology News(10 mins):
(Date:10/5/2018)... ... October 04, 2018 , ... Earthres Group, Inc., a ... the company’s brand identity and better reflects its current breadth of markets and ... engineering expertise and related support services to clients in seven market sectors, and ...
(Date:10/2/2018)... ... 2018 , ... The Alliance for Clinical Research Excellence and ... standards and testing of procedures for voluntary accreditation of clinical research sites. The ... Quality Management Systems and Chief Quality Officer, is underway in association with ...
(Date:9/27/2018)... N.J. (PRWEB) , ... September 26, 2018 , ... ... DNA testing are way ahead of their primary care physicians, according to a ... For this study, patients and doctors were asked about consumer adoption of fitness ...
(Date:9/24/2018)... ... ... ReGrow Helmet , the most advanced laser hair treatment device, is ... regrowth in the comfort of one’s home. Early campaign backers will save 40% off ... design and advanced technology of the ReGrow Helmet will lead the industry in engineering ...
Breaking Biology Technology:
Cached News: