HpaII (

IntEnz IntEnz (Integrated relational Enzyme database) contains data on enzymes organized by enzyme EC number and is the official version of the Enzyme Nomenclature system developed by the International Union of Biochemistry and Molecular Biology The ...

:
EC 3.1.21.4
') is a

restriction enzyme A restriction enzyme, restriction endonuclease, REase, ENase or'' restrictase '' is an enzyme that cleaves DNA into fragments at or near specific recognition sites within molecules known as restriction sites. Restriction enzymes are one class o ...

obtained from the microorganism ''

Haemophilus parainfluenzae ''Haemophilus parainfluenzae'' is a species of'' Haemophilus''. It is one of the HACEK organisms. ''H. parainfluenzae'' is an opportunistic pathogen that has been associated with endocarditis, bronchitis, otitis, conjunctivitis, pneumonia, ab ...

''. It is a DNA restriction enzyme, therefore it has the ability to cut the DNA from certain region as demonstrated below. It has the ability to produce

cohesive end DNA ends refer to the properties of the ends of linear DNA molecules, which in molecular biology are described as "sticky" or "blunt" based on the shape of the complementary strands at the terminus. In sticky ends, one strand is longer than the ...

s, which are rather useful in constructing

plasmid A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; how ...

s. HpaII will not cut sites that have been methylated by SssI methyltransferase or HpaII methyltransferase. When the sites have been methylated by MspI methyltransferase, the enzyme will cut 300 times slower than unmethylated DNA and 50 times slower if the DNA is hemi-methylated. McClelland, M., Nelson, M., Raschke, E. (1994). Nucleic Acids Research 22, No. 17, 3640-3659. This feature is exploited for determination of the clonal origin of a

mammalian Mammals () are a group of vertebrate animals constituting the class (biology), class Mammalia (), characterized by the presence of mammary glands which in Female#Mammalian female, females produce milk for feeding (nursing) their young, a ...

female tumor through HUMARA assay.

References

{{restriction enzyme Restriction enzymes