Dopamine, acting via cyclic adenosine 3':5'-monophosphate (cAMP), has been shown to enhance a kainate-gated ionic conductance in white perch retinal horizontal cells in vitro. To determine whether this effect involves stimulation of a protein kinase, kainate-gated currents were observed in cultured horizontal cells that were dialyzed with the catalytic subunit of cAMP-dependent protein kinase. ...

BsrDI and BtsI restriction endonucleases recognize and cleave double-strand DNA at the sequences GCAATG (2/0) and GCAGTG (2/0), respectively. We have purified and partially characterized these two enzymes, and analyzed the genes that encode them. BsrDI and BtsI are unusual in two respects: each cleaves DNA as a heterodimer of one large subunit (B subunit) and one small subunit (A subunit); and,...

Eukaryotic DNA replication requires the coordinated activity of the multi-subunit DNA polymerases: Pol alpha, Pol delta and Pol epsilon. The conserved catalytic and regulatory B subunits associate in a constitutive heterodimer that represents the functional core of all three replicative polymerases. Here, we combine X-ray crystallography and electron microscopy (EM) to describe subunit interact...

The folding of ribosomal RNAs is central to the biogenesis mitoribosome and a complex, stepwise process. Five recent cryo-EM studies detail late steps maturation human mitoribosomal large subunit RNA that forms catalytic core ribosome: peptidyl transferase center (PTC).

The RNA splicing and processing endonuclease from Nanoarchaeum equitans (NEQ) belongs to the recently identified (alphabeta)(2) family of splicing endonucleases that require two different subunits for splicing activity. N. equitans splicing endonuclease comprises the catalytic subunit (NEQ205) and the structural subunit (NEQ261). Here, we report the crystal structure of the functional NEQ enzym...

Eukaryotic chromosomes end in short nucleotide repeats that are added by the enzyme telomerase. The catalytic subunit of telomerase has been shown to be most closely related in sequence to reverse transcriptases encoded by eukaryotic retrotransposable elements. This raises the question as to whether the telomerase subunit was present in the first eukaryotes or was derived during early eukaryote...

The herpes simplex virus DNA polymerase consists of two subunits--a catalytic subunit and an accessory subunit, UL42, that increases processivity. Mutations affecting the extreme C terminus of the catalytic subunit specifically disrupt subunit interactions and ablate virus replication, suggesting that new antiviral drugs could be rationally designed to interfere with polymerase heterodimerizati...

NBD-C1 (7-chloro-4-nitro-2,1,3-benzoxadiazole) inactivates the catalytic subunit of adenosine 3’,5’-cyclic monophosphate (CAMP) depthdent protein kinase isolated from bovine brain by covalent modification. The reaction follows pseudo-first-order kinetics. The pseudo-first-order rate constant (k8p,,) shows a hyperbolic dependence on NBD-Cl concentration, suggesting formation of a reversible comp...