E. coli ~35: human ~52 kDa
||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
|| Netzer WJ, Hartl FU. 1998. Protein folding in the cytosol: chaperonin-dependent and -independent mechanisms. Trends Biochem. Sci. 23: 68–73PubMed ID9538692
||P.326 right column top paragraph: "Although domain size was conserved during evolution, the average size of proteins increased from ∼35 kDa in bacteria such as Escherichia coli to ∼52 kDa in humans (primary source). Translational pausing may also enhance the efficiency of cotranslation folding, but the significance of this phenomenon in vivo is still under investigation (refs 34, 39-42)."