NlaIII is a type II restriction enzyme isolated from Neisseria lactamica.[1] As part of the restriction modification system, NlaIII is able to prevent foreign DNA from integrating into the host genome by cutting double stranded DNA into fragments at specific sequences.[2] This results in further degradation of the fragmented foreign DNA and prevents it from infecting the host genome.[3]

Recognition site of NlaIII with a red line indicating the cutting pattern

NlaIII recognizes the palindromic and complementary DNA sequence of CATG/GTAC and cuts outside of the G-C base pairs. This cutting pattern results in sticky ends with GTAC overhangs at the 3' end.[4]

Characteristics

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NlaIII from N. lactamica contains two key components: a methylase and an endonuclease.[5] The methylase is critical to recognition, while the endonuclease is used for cutting.[5] The gene (NlaIIIR) is 693 bp long and creates the specific 5’-CATG-3’ endonuclease.[6] A homolog of NlaIIIR is iceA1 from Helicobacter pylori.[6] In H. pylori, there exists a similar methylase gene called hpyIM which is downstream of iceA1.[7] ICEA1 is an endonuclease that also recognizes the 5’-CATG-3’ sequence.[6] IceA1 in H. pylori is similar to that of NlaIII in N. lactamica.

NlaIII contains an ICEA protein that encompasses the 4 to 225 amino acid region.[6][8] H. pylori also contains the same protein.[9] H. pylori infection often leads to gastrointestinal issues such as peptic ulcers, gastric adenocarcinoma and lymphoma.[10] Researchers speculate that ICEA proteins serve as potential markers for gastric cancer [7]

Isoschizomers

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NlaIII isoschizomers recognize and cut the same recognition sequence 5’-CATG-3’.[11] Endonucleases that cut at this sequence include:

  • Fael
  • Fatl
  • Hin1II
  • Hsp92II
  • CviAII
  • IceA1

Applications

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NlaIII can be used in many different experimental procedures[12] such as:

References

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  1. ^ "nlaIIIR - Type-2 restriction enzyme NlaIII - Neisseria lactamica - nlaIIIR gene & protein". www.uniprot.org. Retrieved 2020-11-05.
  2. ^ Sitaraman, Ramakrishnan (2016). "The Role of DNA Restriction-Modification Systems in the Biology of Bacillus anthracis". Frontiers in Microbiology. 7: 11. doi:10.3389/fmicb.2016.00011. ISSN 1664-302X. PMC 4722110. PMID 26834729.
  3. ^ Berg, Jeremy M.; Tymoczko, John L.; Stryer, Lubert (2002). "Restriction Enzymes: Performing Highly Specific DNA-Cleavage Reactions". Biochemistry. 5th Edition.
  4. ^ a b Jack J. Pasternak (14 June 2005). An Introduction to Human Molecular Genetics: Mechanisms of Inherited Diseases. John Wiley & Sons. ISBN 978-0-471-71917-5.
  5. ^ a b Morgan, R. D.; Camp, R. R.; Wilson, G. G.; Xu, S. Y. (1996-12-12). "Molecular cloning and expression of NlaIII restriction-modification system in E. coli". Gene. 183 (1–2): 215–218. doi:10.1016/s0378-1119(96)00561-6. ISSN 0378-1119. PMID 8996109.
  6. ^ a b c d Xu, Qing; Morgan, R. D.; Roberts, R. J.; Xu, S. Y.; van Doorn, L. J.; Donahue, J. P.; Miller, G. G.; Blaser, Martin J. (2002-09-01). "Functional analysis of iceA1, a CATG-recognizing restriction endonuclease gene in Helicobacter pylori". Nucleic Acids Research. 30 (17): 3839–3847. doi:10.1093/nar/gkf504. ISSN 0305-1048. PMC 137426. PMID 12202769.
  7. ^ a b Xu, Q.; Peek, R. M.; Miller, G. G.; Blaser, M. J. (1997-11-01). "The Helicobacter pylori genome is modified at CATG by the product of hpyIM". Journal of Bacteriology. 179 (21): 6807–6815. doi:10.1128/jb.179.21.6807-6815.1997. ISSN 0021-9193. PMC 179612. PMID 9352933.
  8. ^ "UniProtKB - Q51083 (T2N3_NEILA)". UniProt. Retrieved December 2, 2020.
  9. ^ Wong, Benjamin Chun Yu; Yin, Yan; Berg, Douglas E.; Xia, Harry Hua-Xiang; Zhang, Jian Zhong; Wang, Wei Hong; Wong, Wai Man; Huang, Xiao Ru; Tang, Vera Shun Yim; Lam, Shiu Kum (2001). "Distribution of Distinct vacA, cagA and iceA Alleles in Helicobacter pylori in Hong Kong". Helicobacter. 6 (4): 317–324. doi:10.1046/j.1523-5378.2001.00040.x. ISSN 1523-5378. PMID 11843964. S2CID 10084164.
  10. ^ Kusters, Johannes G.; Vliet, Arnoud H. M. van; Kuipers, Ernst J. (2006-07-01). "Pathogenesis of Helicobacter pylori Infection". Clinical Microbiology Reviews. 19 (3): 449–490. doi:10.1128/CMR.00054-05. ISSN 0893-8512. PMC 1539101. PMID 16847081.
  11. ^ "Enzyme Finder". New England Biolabs. Retrieved 23 October 2020.
  12. ^ "Hin1II (NlaIII) (5 U/µL)". Thermo Fisher Scientific. Retrieved November 3, 2020.