eukaryotes ~4: bacteria ~20 amino acids/sec
||Kim YE, Hipp MS, Bracher A, Hayer-Hartl M, Hartl FU. Molecular chaperone functions in protein folding and proteostasis. Annu Rev Biochem. 201382:323-55. doi: 10.1146/annurev-biochem-060208-092442. p.326 right column top paragraphPubMed ID23746257
|| Hartl FU, Hayer-Hartl M. 2009. Converging concepts of protein folding in vitro and in vivo. Nat. Struct. Mol. Biol. 16: 574–81 doi: 10.1038/nsmb.1591.PubMed ID19491934
||P.326 right column top paragraph: "Whereas single-domain proteins complete folding posttranslationally (after chain termination and release from the ribosome), proteins consisting of multiple domains may fold cotranslationally as the domains emerge sequentially from the ribosome. Sequential folding of the domains prevents the formation of unproductive intermediates resulting from nonnative interactions between concomitantly folding domains (refs 36, 37). For the multidomain protein firefly luciferase, sequential domain folding results in a dramatic acceleration of folding speed (refs 6, 7, 36). The slower translation speed in eukaryotes (∼4 amino acids s^−1) compared with bacteria (∼20 amino acids s^−1) (primary source), together with evolutionary adaptations of the chaperone machinery, may facilitate cotranslational folding for domains with slower folding kinetics and thus may have contributed to the explosive evolution of multidomain proteins in eukaryotes."