Complementation on Ribosomes
This extract was created in the absence of an abstract.
Excerpt
INTRODUCTION
Many polypeptide chains do not acquire enzymatic activity until they aggregate into a multimeric protein molecule. In these cases, the “active site” must spread over more than one chain, or, as we now guess more likely, aggregation causes conformational changes leading to enzymatic activity. Among these proteins is the bacterial enzyme β-galactosidase, whose smallest active form sediments at 16S and has a molecular weight generally thought to be about 500,000. Its subunit construction is clearly shown by its disaggregation into 4 subunits by 8 M urea (Zipser, 1963). Each of these urea subunits may have several polypeptide chains.
Here we present evidence that subunit aggregation to reform active enzyme can occur when one of the subunits is firmly attached to a ribosome. Since the attachment of the monomer to the ribosome suggests that the synthesis of the momomer chain is incomplete, these experiments hint that the growing polypeptide chains...
