Isolation and characterization of Tn5-induced mutants of Pseudomonas paucimobilis UT26 defective in gamma-hexachlorocyclohexane dehydrochlorinase (LinA)

Biosci Biotechnol Biochem. 1993 May;57(5):703-9. doi: 10.1271/bbb.57.703.


Pseudomonas paucimobilis UT26 grows on gamma-hexachlorocyclohexane (gamma-HCH) as a sole source of carbon and energy. Tn5 mutation was introduced into UT26, and two kinds of mutants defective in gamma-HCH degradation were phenotypically isolated; one (UT64) completely lacked the activity to degrade gamma-HCH, while the other (UT61) retained a very low level of activity. Tagging and sequencing analysis showed that both mutants had a Tn5 insertion at the same site of the linA (gamma-HCH dehydrochlorinase encoding) gene. However, UT61 had an additional rearrangement, which could be the cause of its retaining a low level of activity. An in vitro complementation test with a crude extract from UT64 plus partially purified LinA protein showed that LinA was essential not only for the first-step reaction (gamma-HCH to gamma-pentachloro-cyclohexene; gamma-PCCH), but also for the second-step reaction (gamma-PCCH to compound B) of gamma-HCH degradation in UT26.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Blotting, Southern
  • Culture Media
  • DNA Transposable Elements*
  • Gene Expression Regulation, Bacterial
  • Genetic Complementation Test
  • Hexachlorocyclohexane / metabolism*
  • Lyases / genetics*
  • Lyases / metabolism
  • Molecular Sequence Data
  • Mutation
  • Phenotype
  • Pseudomonas / enzymology
  • Pseudomonas / genetics*
  • Restriction Mapping


  • Culture Media
  • DNA Transposable Elements
  • Hexachlorocyclohexane
  • Lyases
  • DDT-dehydrochlorinase