Article Summaries:
Structure and Function of Type 2 restriction endonucleases
Currently,
there are more than 3000 type 2 restriction endonucleases discovered. Restriction enzymes cleave specific regions
of DNA. Specifically, type 2 restriction endonucleases do not require ATP
Hydrolysis and there are also subdivisions that are more specific categories.
Bgl2 is part of the EcoRI family as a sub category for type 2 restriction
endonucleases. The sequence cleaved by Bgl2 is
AGATCT, and when it cleaves, there are sticky ends. The binding site of Bgl2 encircles the DNA
and approaches from the major groove side of the DNA and it also comes in
contact with the minor groove side. This
article also goes into the specific residues that interact with each part of
the DNA. Collectively in the entire interaction with DNA, there are 5 carbon
bonds with the minor groove and 14 hydrogen bonds to the major groove. “Altogether there are 28 backbone contacts, 20
of them are water-mediated”
Pingoud, Alfred, and Albert Jeltsch. "Structure and
Function of Type 2 Restricstion Endonucleases." Nucleic Acids Reasearch
29.18 (2001): 3705-27. Print.
Institut für Biochemie (FB 08),
Justus-Leibig-Univerität, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany
Purification and Properties of the Restriction Endonuclease BglII from Baccillus globigii
BglI and
BglII were first discovered in Baccillus
globigii and found to be useful in
recombinant DNA experiments. Both BglI and BglII recognize the same section of
DNA. This paper discusses the
purification of BglII and properties discovered for BglII. For enzymatic
activity for BglII, Magnesium must be present. Sodium Chloride is also required
for some stimulation of enzymatic activity. The researchers found that the optimum
pH is higher than most other restrictions enzymes, but they also say that this
optimum might be different when other labs research it. They tested other ions to see if they would
activate enzymatic activity and the ones that did were Mn2+, Zn2+,
Cd2+, and Ni2+; and Mn2+ was observed to be
better than low concentrations of Mg2+. They also looked at the interactions with
DNA. They found that BglII does not significantly unwind DNA and that it
cleaves both strands almost simultaneously.
Imber, Roland, and Thomas A. Bickle. "Purification and
Properties of the Restriction Endonuclease BglII from Baccillus globigii."
Federation of the Societies of Biochemistry and Molecular Biology 117
(1981): 395-99. Print.
Microbiology Department, Biozentrum, University of Basel
Structure of Free BglII reveals an unpredicted scissor-like
motion for opening and endonuclease
This
article analyses the movement of BglII in a scissor like motion. BgkII has 223
amino acids in its structure and it is a dimer, made up of two units. Each unit
has two loops that enclose the DNA by reaching around the minor groove. The active
site residues are only exposed for catalysis when a group called the lever is
in the up position, interacting with the DNA.
Lukacs, Christine M., Rebecca Kucera, Ira Schildkraut, and
Aneel k. Aggarwal. "Structure of Free BglII reveals an unpredicted
scissor-like motion for opening and endonuclease." Nature Publishing
Group 8.2 (2001). Print.
Structural Biology Program, Department of Physiology and
Biophysics, Mount Sinai School of
Medicine
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