A variety of amino-terminal fusions maintain enzymatic activity (or produce enzymatically active breakdown products) including those fused to codon 12 of NPT [ 48- 52].
In vitro reconstituted forms of topoisomerase with only the NH2-terminal domain deleted (topo70) or both the NH2-terminal and the linker domains deleted (topo58/6.3), maintain enzymatic activity [13].
Although RBD mutants of p110α fail to bind KRAS, they still maintain enzymatic activity.
By extracting total embryo protein under conditions that maintain enzymatic activity, we were able to perform protease assays using fluorogenic gelatin and collagen IV substrates.
Only over the past decade was convincing evidence found for these enzymes as to their ability to migrate to the nucleus where they maintain enzymatic activity 95, 98, 111, 113, 114, 116, 120, 129.
GerP proteins encoded within this operon are not predicted to maintain enzymatic activities, and yet gerP mutants have severe germination defects in other Bacillus species [23].
The idea behind these efforts is to promote formation of lobular structures with apical-basal polarization (including bile canaliculi formation) of hepatocytes and additionally to maintain enzymatic activities.
Maintaining NA enzymatic activity levels is critical and numerous conserved residues were located at the oligomerization interface; however, these mutations did not affect NA enzymatic activity levels or NA cellular localization, but rather affected the stability of NA oligomerization, suggesting that the oligomerization of NA is essential for viral viability.
Bmi-1 is part of the multiprotein histone E3 ubiquitin ligase complex, polycomb repressor complex 1 (PRC1; see Figure 4) and is important for maintaining the enzymatic activity of the complex as well as its structure [ 38], while Ezh2 is a component of PRC2 involved in methylation of lysine 27 of histone H3 (H3K27) and recruitment of PRC1.
This result is consistent with amino acid substitution analysis of BY-kinases and supports the notion that these enzymes evolve fast and only conserve at essential sites to maintain core enzymatic activity.
