Month: September 2022

VIRAL PARASITES. "Every organism is constantly under the attack of viral infections because viruses outnumber cellular organisms by at least an order of magnitude. It has been estimated that viruses kill approximately one fifth of the marine biomass on a daily basis. Furthermore, viruses are the leading cause of infectious diseases." But the vast majority of viruses are benign. https://lnkd.in/dmGjENv View in LinkedIn

LIMITED VIRAL LINEAGES. "Viruses have a crucial role in controlling the evolution of cellular organisms owing to their high abundance and genetic diversity. However, cryoelectron microscopic and crystallographic studies have revealed that this genetic diversity may be reduced to a limited number of structure-based viral lineages." https://lnkd.in/dmGjENv View in LinkedIn

STRUCTURAL COMMONALITY. "Structural comparison of the major subunits of viral capsids suggests common origins for viruses that infect hosts from different domains of life. One such viral structure-based lineage is the HK97-like group." http://www.sciencedirect.com/science/article/pii/S0042682215001920 View in LinkedIn

MOST COMMON FOLD ON PLANET. "Most proteins fold like this. By the sheer number of viruses that exist, people estimate this to be the most common fold of a protein on earth. It’s known as the HK97 fold. Viruses with the HK97 fold infect hosts throughout all kingdoms of life, suggesting it’s been around for billions of years." https://lnkd.in/d6j6P8g View in LinkedIn

MOST COMMON BIOLOGICAL STRUCTURE. "A protein fold that may be the most abundant biological structure on Earth. Surprisingly, the majority (67%) of the metaproteomic spectra were derived from just five environmentally dominant PCs. With a combination of sequence- and structural modeling-based annotation, these PCs are now predominantly identified as putative capsid proteins of tailed viruses containing the most abundant biological structure on Earth, the HK97-like protein fold." (PC = protein cluster). https://lnkd.in/dNAibqS View in LinkedIn

STRUCTURAL AND FLEXIBLE. "Nature's favorite building block: Deciphering folding and capsid assembly of proteins with the HK97-fold. For many (if not all) bacterial and archaeal tailed viruses and eukaryotic Herpesvirdae the HK97-fold serves as the major architectural element in icosahedral capsid formation while still enabling the conformational flexibility required during assembly and maturation." https://lnkd.in/dBCqqe2 View in LinkedIn

BACTERIAL VIRUS. "HK97 is a bacterial virus, bacteriophage, known to infect Escherichia coli and related bacteria. The capsid protein of HK97, gp5, cross-links upon maturation to form a concatenated chain-mail like structure. The bacteriophage undergoes a maturation process upon DNA packaging during which it expands by nearly 5 nm and changes from spherically symmetrical to icosahedrally symmetrical." https://lnkd.in/d9B2fAQ View in LinkedIn

"CHAINMAIL is a system formed by concatenated rings. Chainmail in the form of interlocking rings of metal was used by medieval knights to protect their bodies from external forces in battle. The term protein chainmail was coined to explain how capsid proteins of HK97 form large complexes that behave abnormally under biochemical analyses. Later, the X-ray structure revealed how the polypeptide chains are arranged in the HK97 mature capsid to form concatenated rings." http://www.aimspress.com/article/10.3934/biophy.2015.2.200/fulltext.html View in LinkedIn

NO WEAKEST LINK. "Like the armor, chainmail in viruses provides a thin yet durable layer to endure the internal force exerted by the encapsulated dsDNA. In both cases, chainmail may have been developed for its ability to maintain structural integrity. Indeed, unlike Borromean rings, breaking a single ring in a chainmail does not affect the integrity of the whole mail." (dsDNA = double stranded DNA). http://www.aimspress.com/article/10.3934/biophy.2015.2.200/fulltext.html View in LinkedIn

CONSIDERABLE STRUCTURAL FLEXIBILITY. “Variations of the HK97-like fold can occur when the basic building blocks are connected in different order. Additionally, extra domains can be inserted at the E-loop or at the ends of the building blocks." http://www.aimspress.com/article/10.3934/biophy.2015.2.200/fulltext.html View in LinkedIn