Hunter Barrat

About Hunter Barrat

Hunter enjoys the collaborative process of writing about biomedical research topics.

Protein Alphabet: A Picture Is Worth One Letter

It’s back-to-school time. That means learning lots of new facts and figures. In science, terms tend to be several syllables, sometimes with a Latin word thrown into the mix. As a result, many are referred to by their acronyms, such as DNA—short for deoxyribonucleic acid. This makes them easier both to remember and to say.

Researcher Mark Howarth Exit icon of Oxford University, has taken this a step further. Searching through information stored in the NIGMS-funded Protein Data Bank Exit icon, he curated a 3-D protein alphabet. It’s a set of 26 protein crystal structures that look like they were fashioned from bits of rainbow-colored curly ribbon. This 3-D alphabet helps us see what different protein strands look like, and explains terms and concepts relating to protein structure and function.

Proteins are molecules that play important roles in virtually every activity in the body. They form hair and fingernails, carry oxygen in the blood, enable muscle movement and much more. Although proteins are made of long strands of small molecules called amino acids, they do not remain as a straight chain. Some proteins are composed of multiple amino acid strands that wind together in the completed protein. The strands twist, bend and fold into a specific shape, and the protein’s structure enables it to perform its task. For instance, the “Y” shape of antibodies helps these immune system proteins bind to foreign molecules such as bacteria or viruses while also drawing in other immune system molecules. Continue reading

Researchers Score Goal with New Atomic-Scale Model of Salmonella-Infecting Virus

An atomic-scale model of a virus that infects the Salmonella bacterium. Credit: C. Hryc and the Chiu Lab, Baylor College of Medicine.

This sphere could be a prototype design for the 2018 World Cup official match soccer ball, but you won’t see it dribbled around any soccer fields. The image is actually an atomic-scale model of a virus that infects the Salmonella bacterium. Like a soccer ball, both are approximately spherical shapes created by a combination of hexagonal (six-sided) and pentagonal (five-sided) units. Wah Chiu, a biochemist at Baylor College of Medicine, and his colleagues used new computational methods to construct the model from more than 20,000 cryo-electron microscopy (cryo-EM) images. Cryo-EM is a sophisticated technique that uses electron beams for visualizing frozen samples of proteins and other biological specimens.

The researchers’ model, published in a recent issue of PNAS, shows the virus’ protein shell, or capsid, that encloses the virus’ genetic material. Each color shows capsid proteins having the same interactions with their neighbors. The fine resolution allowed researchers to identify the protein interactions essential to building a stable shell. They developed a new approach to checking the accuracy and reliability of the virus model and reporting what parts are the most certain. The approach could be used to evaluate other complex biological structures, potentially leading to better quality models and new avenues for drug design and development.

This research is funded in part by NIH under grants R01GM079429, P01GM063210, P41GM103832, PN2EY016525, T15LM007093.

Birthdays, Nobel Prizes and Basic Research

James D. Watson
James D. Watson. Credit: Wikimedia Commons, Cold Spring Harbor Laboratory.

April 6 is the birthday of two Nobel Prize winners in physiology or medicine—James Watson and Edmond H. Fischer. They have also both been NIGMS-supported researchers.

Double helix model
In 1953, Watson and Crick created their historic model of the shape of DNA: the double helix. Credit: Cold Spring Harbor Laboratory archives.

James D. Watson, born on this day in 1928, was honored with the Nobel Prize in 1962. He shared it with Francis H. Compton Crick and Maurice Wilkins “for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material.” This laid the groundwork for future discoveries. In the early 1950s, Wilkins and another scientist, Rosalind Franklin, worked to determine DNA’s structure. In 1953, Watson and Crick discovered its shape as a double helix. This twisted ladder structure enabled other researchers to unlock the secret of how genetic information is stored, transferred and copied. Franklin is widely recognized as having played a significant role in revealing the physical structure of DNA; due to her death at age 37 in 1958, Franklin did not earn a share of the prize. Read more about DNA. Continue reading

On Pi Day, Computational Biologists Share What They Love About Math

Another cool fact about Pi: The mirror reflection of the numbers 3 1 4 spells out P I E.

Why do math lovers around the world call March 14 “Pi Day”? Because Pi, the ratio of a circle’s circumference to its diameter, is 3.14. Pi is a Greek letter (π) that represents a constant in math: All circles have the same Pi, regardless of their size. Pi has been calculated out to as many as 1 trillion digits past the decimal, and it can continue forever without repetition or pattern.

In honor of Pi Day, we asked several biomedical researchers in the field of computational biology to tell us why they love math and how they use it in their research. Continue reading