Minor improvements to our previous estimate bsky.app/profile/joan... of which amino acids are enriched vs depleted in LUCA (indicating their order of appearance) strengthened the signal that small amino acids came first. 2/13
Joanna MaselWe identified protein domains in LUCA (Last Universal Common Ancestor). Their distinctive amino acid usage reveals the order amino acids were added to the genetic code, based mostly on size. Older proteins hint at earlier alternative codes. 1/15 @seekingluca.bsky.social www.pnas.org/doi/10.1073/...