You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
Join the #1 community for gun owners of the Northwest
We believe the 2nd Amendment is best defended through grass-roots organization, education, and advocacy centered around individual gun owners. It is our mission to encourage, organize, and support these efforts throughout Oregon, Washington, Idaho, Montana, and Wyoming.
Discuss firearms and all aspects of firearm ownership
Join others in organizing against anti-gun legislation
Buy, sell, and trade in our classified section
Find nearby gun shops, ranges, training, and other resources
Discover free outdoor shooting areas
Stay up to date on firearm-related events
Share photos and video with other members
...and much more!
PstI is a type II restriction endonuclease isolated from the Gram negative species, Providencia stuartii. It is the isoschizomer of Streptomyces albus P restriction enzyme SalPI. It cleaves DNA at the recognition sequence 5′-CTGCA/G-3′ generating fragments with 3′-cohesive termini. This cleavage yields sticky ends 4 base pairs long. PstI is catalytically active as a dimer. The two subunits are related by a 2-fold symmetry axis which in the complex with the substrate coincides with the dyad axis of the recognition sequence. It has a molecular weight of 69,500 and contains 54 positive and 41 negatively charged residues.
The PstI restriction/modification (R/M) system has two components: a restriction enzyme that cleaves foreign DNA, and a methyltransferase which protect native DNA strands via histone methylation. The combination of both provide a defense mechanism against invading viruses. The methyltransferase and endonuclease are encoded as two separate proteins and act independently. In the PstI system, the genes are encoded on opposite strands and hence must be transcribed divergently from separate promoters. The transcription initiation sites are separated by only 70 base pairs. A delay in the expression of the endonuclease relative to methylase is due to the inherent differences of the two proteins. The endonuclease is a dimer, requiring a second step for assembly, whereas the methylase is a monomer.
PstI is functionally equivalent to BsuBI. Both enzymes recognize the target sequence 5'CTGCAG. The enzyme systems have similar methyltransferases (41% amino acid identity), restriction endonucleases (46% amino acid identity), and genetic makeup (58% nucleotide identity). These observations suggest a shared evolutionary history.
When examining the preferential double strand cleavage of DNA, the restriction endonuclease PstI bind to pSM1 plasmid DNA.
Nice optic, still have another at home here. This is extra and was on that sig upper I have for sale both fired under 40 rounds.
red illumination with variable brightness
comes with see thru lens caps, MKM throw lever, Redfield Tactical SPR Mount (knobs, may have some wear from...
For sale is a Gen 1 6-24x50 Vortex Viper PST first focal plane scope with the EBR-1 (MOA) Reticle. Almost pristine condition with very few rounds fired underneath it (around 150). Very minor (barely noticeable) ring marks on tube. $350
Also for sale are the badger ordnance rings as seen in the...
vortex viper pst 6x24x50
illuminated ebr-1c mrad reticle
first focal plane
warne maxima scope rings
includes all packaging sunshade lense cover etc
only trade interests
I will add cash on my end trades for custom actions ex. kelbly, stiller, arc, bighorn, etc. or...
SOLD to @Lazyfaire!
Up for sale is a Vortex Viper PST 4-16x50 2nd Focal Plane with illuminated EBR-1 MOA Reticle. 30mm tube. 1/4 MOA turrets.
Comes with original box, paperwork, sunshade, zero stop shims, vortex logo pin and bikini covers.
100% mechanical function. Scope tracks and holds...
I'm happy to announce the tentative date and time of the Northwest Firearms V4 Upgrade is Monday, July 15th, beginning at 3AM PST. While we hope get the site back up and running as soon as possible, it's hard to predict exactly how long the site will be down. If everything goes as planned it...
Up for sale is a Vortex PST Gen I 6-24 EBR-2C FFP MRAD. Been on the rifle for 2 years, still in near perfect condition. Comes with a lot of shims. Also comes with Butler Creek rear flip cap, and Vortex Switchview magnification lever. No front cap. $400 firm. Not looking for trades unless it’s a...
Have been looking for a long shot scope and came across this pricing. These are the Gen 2 models w/ FFP, but there are others on the site. I paid $250 (25% under list).
These are the PST Gen 2 5-25 x 50 scopes (MOA & MRAD reticles)
Product Comparison - EuroOptic.com
Up for sale is a used, but in great condition optic. Vortex Viper Gen 2. 5-25x50 illuminated Mrad. Vortex Precision Matched Rings and Defender flip caps. I still have the box and accessories. I will leave the scope leveled in the rings. Had been mounted on a Tikka 6.5 Creedmoor for about 200...
I’m looking for help from the brain trust here.
I just picked up a vortex viper pst ii and I’m trying to decide which rifle to put it on. Both are good candidates.
My goal from both rifles is to be proficient at 600 yards from a solid rest with a dream of doing some 1000 yard shots. (Though...
Want to sell for 800 shipped. Throw lever not included. Open to firearm trade offers but must be willing to ship unless within reasonable distance of Klamath Falls, OR.
Add 3.5% for PayPal G&S or any additional insurance.
Hi I have a as new in box. Vortex Viper PST 6x24x50mm illumanited mil-dot. Scope. Comes with sun shade, zero stop shims butler creek lens covers. Lifetime warranty. $525 shipped PayPal gift or fee or postal money order can do a face to face in Salem
Rifle not included