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Biosynthesis of Bacterial Cellulose
Inder M. Saxena and R. Malcolm Brown, Jr.
Section of Molecular Genetics and Microbiology,
University of Texas at Austin, Austin, Texas
CONTENTS
Introduction.............................................................................................................. 2
Gluconacetobacter xylinus.is.a.Unique.Cellulose-Producing.Bacterium............3
Structure.of.Cellulose.I.is.Determined.by.the.Cell-Directed.Assembly.
of.Glucan.Chains...................................................................................................... 4
Cellulose.Synthesis.in.Bacteria.is.Catalyzed.by.the.
Membrane-Associated.Cellulose.Synthase.......................................................... 5
Genes.for.Cellulose.Biosynthesis.can.be.Classified.into.Three Groups.
Based.on.the.Function.of.the.Codified.Proteins..................................................6
What.is.Known.About.the.Proteins.Involved.in.Cellulose.Synthesis.in.
Bacteria?. .................................................................................................................... 9
“Guilt.by.Association”.Model.of.the.G. xylinus.Cellulose-Synthesizing.
Complex.................................................................................................................. 11
Many.Unanswered.Questions.Remain............................................................... 12
Many.Bacteria.Have.Genes.for.Cellulose.Synthesis,.but.Only.a.
Few Produce.Cellulose.......................................................................................... 13
Acknowledgment. .................................................................................................. 15
References. ............................................................................................................... 15
Since. the. first. identification. of. genes. for. cellulose. biosynthesis. in.
Gluconacetobacter xylinus.more.than.20.years.ago,.homologous.sequences.
have. been. identified. in. the. genomes. of. a. large. number. of. bacterial.
. species..The.genes.for.cellulose.biosynthesis.are.organized.in.an.operon.
consisting. of. three. to. four. genes. and. this. organization. is. conserved.
in. most. bacteria.. The. first. gene. in. the. operon. encodes. for. the. enzyme.
. cellulose.synthase.and.so.far.this.is.the.only.protein.with.a.known.function.in.cellulose.biosynthesis..Although.genetic.analysis.demonstrated.a.
role.in.cellulose.biosynthesis.for.the.other.genes.in.the.operon,.the.exact.
mined..Genetic,.biochemical,.and.structural.data.suggest.that.the.proteins.encoded.by.genes.in.the.operon.are.assembled.as.a.multiprotein.
1
Biosynthesis of Bacterial Cellulose
Inder M. Saxena and R. Malcolm Brown, Jr.
Section of Molecular Genetics and Microbiology,
University of Texas at Austin, Austin, Texas
CONTENTS
Introduction.............................................................................................................. 2
Gluconacetobacter xylinus.is.a.Unique.Cellulose-Producing.Bacterium............3
Structure.of.Cellulose.I.is.Determined.by.the.Cell-Directed.Assembly.
of.Glucan.Chains...................................................................................................... 4
Cellulose.Synthesis.in.Bacteria.is.Catalyzed.by.the.
Membrane-Associated.Cellulose.Synthase.......................................................... 5
Genes.for.Cellulose.Biosynthesis.can.be.Classified.into.Three Groups.
Based.on.the.Function.of.the.Codified.Proteins..................................................6
What.is.Known.About.the.Proteins.Involved.in.Cellulose.Synthesis.in.
Bacteria?. .................................................................................................................... 9
“Guilt.by.Association”.Model.of.the.G. xylinus.Cellulose-Synthesizing.
Complex.................................................................................................................. 11
Many.Unanswered.Questions.Remain............................................................... 12
Many.Bacteria.Have.Genes.for.Cellulose.Synthesis,.but.Only.a.
Few Produce.Cellulose.......................................................................................... 13
Acknowledgment. .................................................................................................. 15
References. ............................................................................................................... 15
Since. the. first. identification. of. genes. for. cellulose. biosynthesis. in.
Gluconacetobacter xylinus.more.than.20.years.ago,.homologous.sequences.
have. been. identified. in. the. genomes. of. a. large. number. of. bacterial.
. species..The.genes.for.cellulose.biosynthesis.are.organized.in.an.operon.
consisting. of. three. to. four. genes. and. this. organization. is. conserved.
in. most. bacteria.. The. first. gene. in. the. operon. encodes. for. the. enzyme.
. cellulose.synthase.and.so.far.this.is.the.only.protein.with.a.known.function.in.cellulose.biosynthesis..Although.genetic.analysis.demonstrated.a.
role.in.cellulose.biosynthesis.for.the.other.genes.in.the.operon,.the.exact.
mined..Genetic,.biochemical,.and.structural.data.suggest.that.the.proteins.encoded.by.genes.in.the.operon.are.assembled.as.a.multiprotein.
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