Glycogenome Reannotation and identification of novel glycoproteins from mycobacterium tuberculosis H37rv

Abstract

Mycobacterium tuberculosis causative agent of human tuberculosis newline TB was responsible for nearly 1 5 million deaths annually accounting newlinealmost 2 4 deaths worldwide The co infection with HIV the evolution of newlinemulti drug resistance MDR extreme drug resistance XDR and more newlinerecently totally drug resistance TDR strains severely hamper the newlineanti tuberculosis therapy The Cell wall associated and secreted newlineglycoconjugates including Lipoarabinomannan LAM Lipomannan LM newlineArabinogalactans AG Phosphoinosidemannoside PIM Cord factor newlineCapsular glucans and Culture filtrate glycoproteins plays an important role in newlinevirulence and pathogenesis of M tuberculosis The current understanding of newlineenzymes involved in the biosynthesis of these functionally important newlineglycoconjugates termed as carbohydrate glycan modifying enzymes newline glycogenome or glycogenes was not sufficient due to lack apparent function newlineassigned to nearly 40 of the coding sequences in M tuberculosis genome newlineHere we report the use of comprehensive Bioinformatics workflow for newlinereannotation of all unknown function proteins from M tuberculosis H37Rv newlinegenome Our analysis predicted 106 novel putative glycan modifying genes newlineFurther non homology based gene cluster analysis was used to predict newlineputative N Glycosylation pathway newlineApart from all the above glycoconjugates M tuberculosis might newlinealso employs several cell wall glycoproteins whose role in virulence and newlinepathogenesis was poorly understood The specific carbohydrate binding newlinelectins immobilized on agarose beads was used to capture cell wall newlineglycoproteins Glyco catch The results showed M tuberculosis cell wall newlinecontains several glycoproteins with terminal mannose ConA PSA and LCU newlineand N Acetylglucosamine DSA Two prominent protein bands eluted from newlinemannose specific ConA lectin was analyzed further using MALDI TOF and newlineESI MS methods The two proteins were identified as hypothetical protein newline 23 KDa and transferase 32