Early research during the decade began to illuminate ubiquitination's wide-ranging role, followed by identification of how ubiquitination functions. And research in the latter part of the decade, led by the authors of these two papers, revealed the importance that RING finger proteins play in the process. The RING finger--which really stands for Really Interesting New Gene1--is a structure found in more than 200 proteins, in which two loops of amino acids are pulled together at their base by eight cysteine or histidine residues that bind two zinc ions.
Ubiquitination was known to involve at least three types of enzymes, but it was unclear what proteins other than ubiquitin interacted in the ubiquitin pathway. Ubiquitination occurs when a ubiquitin-activated enzyme known as E1 bonds with the ubiquitin-conjugating enzyme E2. The ubiquitin then transfers from the E2 enzyme to a catalyzing ubiquitin protein ligase E3, and then onto the substrate. E3s recognize ...
