Main Page

by Eric Martz
After decades of slow progress by many groups, in 2020, AlphaFold2 proved able to accurately predict the detailed structures of two-thirds of single protein domains from their amino acid sequences. Pictured is AlphaFold2's prediction for the ORF8 protein of SARS-CoV-2 (black), compared with a subsequently published X-ray crystallographic structure (colors). ORF8 contributes to virulence in COVID-19.
>>> Visit this page >>>

Y Gu, V Srikanth, AI Salazar-Morales, R Jain, JP O'Brien, SM Yi, RK Soni, FA Samatey, SE Yalcin, NS Malvankar. Nature 2021 doi: 10.1038/s41586-021-03857-w
Geobacter pili were long thought to be electrically conductive protein nanowires composed of PilA-N. Nanowires are crucial to the energy metabolism of bacteria flourishing in oxygen-deprived environments. To everyone's surprise, in 2019, the long-studied nanowires were found to be linear polymers of multi-heme cytochromes, not pili. The first cryo-EM structure of pili (2021) reveals a filament made of dimers of PilA-N and PilA-C, shown. Electrical conductivity of pili is much lower than that of cytochrome nanowires. Evidence suggests that PilA-NC filaments are periplasmic pseudopili crucial for exporting cytochrome nanowires onto the cell surface, rather than the pili serving as nanowires themselves.

>>> Visit I3DC Interactive Visualizations >>>

Above is a transmembrane protein that takes up, into your intestinal cells, orally consumed peptide nutrients and drugs. Its lumen-face (shown above) opens and binds peptide or drug, then closes, while its cytoplasmic face (opposite end from the above) opens to release its cargo into the intestinal cell, which passes it on into the blood circulation.

>>> See more animations and explanation >>>