Mutations in the scaffoldin gene, cipA, of Clostridium thermocellum with impaired cellulosome formation and cellulose hydrolysis: insertions of a new transposable element, IS1447, and implications for cellulase synergism on crystalline cellulose.

ABSTRACT: Mutants of Clostridium thermocellum that had lost the ability to adhere to microcrystalline cellulose were isolated. Six of them that showed diminished ability to depolymerize crystalline cellulose were selected. Size exclusion chromatography of the proteins from the culture supernatant revealed the loss of the supramolecular enzyme complex, the cellulosome. However, denaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis resulted in extracellular protein patterns comparable to those of isolated cellulosomes, except for a missing CipA band. Sequencing of the six mutant cipA genes revealed a new insertion (IS) element, IS1447, belonging to the IS3 family. It was inserted into the cipA reading frame in four different locations: cohesin module 1, two different positions in the ca

SUBMITTER: Zverlov VV 

PROVIDER: S-EPMC2446765 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature