The key difference between isoschizomers and isocaudomers is that isoschizomers recognize and cleave the same restriction or recognition site while isocaudomers recognize slightly different restriction sites and cleave at the same site.
Restriction enzymes or restriction endonucleases are a type of nucleases that cleave double-stranded DNA. They are able to recognize specific sequences called restriction sites, which are palindromic in origin. Bacteria produce restriction enzymes against foreign pathogens, especially against viruses. It is a form of defence mechanism shown by bacteria. Depending on the structure of the enzyme and nature of cuts, there are three types of restriction enzymes as type I restriction enzymes, type II restriction enzymes, and type II restriction enzymes. Moreover, depending on the biochemical activity and source of isolation, there are three types of restriction enzymes as isoschizomers, neoschizomers and isocaudomers.
1. Overview and Key Difference
2. What are Isoschizomers
3. What are Isocaudomers
4. Similarities – Isoschizomers and Isocaudomers
5. Isoschizomers vs Isocaudomers in Tabular Form
6. Summary – Isoschizomers vs Isocaudomers
What are Isoschizomers?
Isoschizomers are a type of restriction enzyme that comes from different sources but recognize and cleave the same restriction site in DNA. Therefore, two isoschizomers have the same recognition site. They cleave at the same site, so they are specific to the same recognition sequence. For example, restriction enzymes SphI and BbuI are two isoschizomers that recognize and cleave at CGTAC/G.
Another pair of isoschizomers is HpaII and MspI. They both recognize the sequence 5′-CCGG-3′ and cleave the DNA. Moreover, BspEI and AccIII are also isoschizomers that are from a Bacillus species and Acinetobacter calcoaceticus, respectively. Isolation of isoschizomers can be done from different bacteria. Since they come from different bacteria, their restriction conditions may be different from one another.
What are Isocaudomers?
Isocaudomers are a type of restriction enzyme that recognizes slightly different sequences, but they cleave at the same site to produce the same ends. Isocaudomers also come from different bacteria. Sau3a and BamHI are a pair of isocaudomers. They produce 5’-GATC-3’ sticky end after cleavage of the same site. Another pair of isocaudomers is NcoI from Nocardia corallina and PagI from Pseudomonas alcaligenes. These two enzymes also bind at different recognition sequences but cut at the same site and produce the same sticky ends. Therefore, producing cutting ends are compatible with each other, and they can be ligated to one another. XhoI, PspXI and SalI are also isocaudomers.
What are the Similarities Between Isoschizomers and Isocaudomers?
- Isoschizomers and isocaudomers are two types of restriction enzymes.
- Two isoschizomers have the same digestion site, similar to two isocaudomers which have the same digestion site.
- They are prokaryotic in origin.
- Both have a restriction recognition site as well as a digestion site.
- They produce ends that are compatible with each other.
- In addition, these enzymes are useful tools in recombinant DNA technology.
What is the Difference Between Isoschizomers and Isocaudomers?
Isoschizomers are restriction enzymes that recognize the same DNA sequence and cleave at the same restriction site, while isocaudomers are restriction enzymes that recognize slightly different DNA sequences but produce the same sticky ends by cutting at the same site. So, this is the key difference between isoschizomers and isocaudomers.
The below infographic tabulates the difference between isoschizomers and isocaudomers.
Summary – Isoschizomers vs Isocaudomers
Isoschizomers are restriction enzymes that recognize the same DNA sequence and cleave at the same site. On the other hand, isocaudomers are restriction enzymes that recognize the slightly different sequences and cleave at the same site producing the same ends. Thus, this is the key difference between isoschizomers and isocaudomers. SphI, BbuI, HpaII and MspI are several examples of isoschizomers while Sau3a and BamHI are two examples of isocaudomers. Both isoschizomers and isocaudomers are naturally produced by bacteria.
1. “EcoRV Restriction Site.rsh” By Ramin Herati – Created with Inkscape (Public Domain) via Commons Wikimedia