The role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153

The locus lex2, comprising lex2A and lex2B, contributes to the phase-variable expression of lipopolysaccharide (LPS) of Haemophilus influenzae and was found to be present in 74% of strains investigated. lex2A contains 5′-GCAA repeats which vary in number from 4 to 46 copies between strains. The locu...

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Main Authors: Griffin, R, Cox, A, Makepeace, K, Richards, J, Moxon, E, Hood, D
Format: Journal article
Language:English
Published: 2003
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author Griffin, R
Cox, A
Makepeace, K
Richards, J
Moxon, E
Hood, D
author_facet Griffin, R
Cox, A
Makepeace, K
Richards, J
Moxon, E
Hood, D
author_sort Griffin, R
collection OXFORD
description The locus lex2, comprising lex2A and lex2B, contributes to the phase-variable expression of lipopolysaccharide (LPS) of Haemophilus influenzae and was found to be present in 74% of strains investigated. lex2A contains 5′-GCAA repeats which vary in number from 4 to 46 copies between strains. The locus was cloned from the serotype b strains RM7004 and RM153 and showed >99% nucleotide sequence identity between these strains and the published lex2 sequence. Disruption of the lex2B gene in strain RM7004 resulted in truncation of some LPS glycoforms, shown by gel fractionation, with only one glycoform reacting with a digalactoside-specific monoclonal antibody, 4C4, compared with four LPS glycoforms in the more elongated LPS of the parent strain. Mass spectrometry and NMR analyses of LPS from the lex2B mutant revealed loss of the terminal digalactoside as well as the second β-glucose extending from the first heptose of the inner core. The authors conclude that Lex2B is the β-(1-4)-glucosyltransferase that adds the second β-glucose to the first β-glucose as part of the oligosaccharide extension from the first heptose of the LPS of strain RM7004. Investigation of the expression of the lex2 locus indicated that the genes are co-transcribed and that both reading frames are required for addition of this second β-glucose in a phase-variable manner.
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spelling oxford-uuid:e7c80915-cd2b-480c-b9ac-04a04cd1f83a2022-03-27T10:41:37ZThe role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e7c80915-cd2b-480c-b9ac-04a04cd1f83aEnglishSymplectic Elements at Oxford2003Griffin, RCox, AMakepeace, KRichards, JMoxon, EHood, DThe locus lex2, comprising lex2A and lex2B, contributes to the phase-variable expression of lipopolysaccharide (LPS) of Haemophilus influenzae and was found to be present in 74% of strains investigated. lex2A contains 5′-GCAA repeats which vary in number from 4 to 46 copies between strains. The locus was cloned from the serotype b strains RM7004 and RM153 and showed >99% nucleotide sequence identity between these strains and the published lex2 sequence. Disruption of the lex2B gene in strain RM7004 resulted in truncation of some LPS glycoforms, shown by gel fractionation, with only one glycoform reacting with a digalactoside-specific monoclonal antibody, 4C4, compared with four LPS glycoforms in the more elongated LPS of the parent strain. Mass spectrometry and NMR analyses of LPS from the lex2B mutant revealed loss of the terminal digalactoside as well as the second β-glucose extending from the first heptose of the inner core. The authors conclude that Lex2B is the β-(1-4)-glucosyltransferase that adds the second β-glucose to the first β-glucose as part of the oligosaccharide extension from the first heptose of the LPS of strain RM7004. Investigation of the expression of the lex2 locus indicated that the genes are co-transcribed and that both reading frames are required for addition of this second β-glucose in a phase-variable manner.
spellingShingle Griffin, R
Cox, A
Makepeace, K
Richards, J
Moxon, E
Hood, D
The role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153
title The role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153
title_full The role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153
title_fullStr The role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153
title_full_unstemmed The role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153
title_short The role of lex2 in lipopolysaccharide biosynthesis in Haemophilus influenzae strains RM7004 and RM153
title_sort role of lex2 in lipopolysaccharide biosynthesis in haemophilus influenzae strains rm7004 and rm153
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