Printer Friendly

New twist in the way a protein turns.

Each protein - a molecule critical to life - consists of a long chain of amino acids folded and twisted to give it a functional shape. In the past, researchers thought these chains could bend in only four ways. Now they know of at least one more.

Biochemists discovered the new kind of folding while examining pectate lyase C, a 353-amino-acid bacterial enzyme that causes potatoes, tomatoes, apples, and tropical plants to rot. Crystallographic studies conducted by Marilyn D. Yoder, Frances Jurnak, and Noel T. Keen at the University of California, Riverside, revealed that the amino acids spiral around to form a molecular corkscrew called a parallel beta helix.

This newly identified spiral is more compressed and its loops wider than those in an alpha helix, the twist in a typical protein, notes Fred E. Cohen of the University of California, San Francisco. It requires about 22 amino acids per turn, compared with the alpha helix's 3.6 amino acids per turn. Other loops extending from this spiral provide platforms for the enzyme's chemical activities, the Riverside team reports in the June 4 SCIENCE.
COPYRIGHT 1993 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1993, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:a fifth functional shape amino acids can take in proteins is discovered
Publication:Science News
Article Type:Brief Article
Date:Jul 31, 1993
Previous Article:Worming through the nervous system.
Next Article:Family ties and risk of breast cancer.

Related Articles
Organic origami: scientists study the art of protein folding.
Gene jumbling yields improved enzymes.
Newly found gene linked to cancer biology.
Seismosaurus proteins: bone of contention.
Crystallized 'coiled coil' zaps leucine zipper.
Water, water everywhere: subtly shaping protein structure and function.
How proteins take shape: guardians give a new twist to protein folding.
An alphabet for a letter-perfect protein.
Hot-blooded proteins: heat-loving enzymes stay cool under stress.
Killer toxin's punch lies below the belt.

Terms of use | Copyright © 2017 Farlex, Inc. | Feedback | For webmasters