%0 Journal Article %1 freiberger_biochemical_2007 %A Freiberger, Friedrich %A Claus, Heike %A GĂźnzel, Almut %A Oltmann-Norden, Imke %A Vionnet, Justine %A MĂźhlenhoff, Martina %A Vogel, Ulrich %A Vann, Willie F %A Gerardy-Schahn, Rita %A Stummeyer, Katharina %D 2007 %J Molecular Microbiology %K , Acid Acids, Adolescent, Alignment, Amino B, Bacterial Binding Child, Conformation, Data, Fusion Humans, Infections, Meningococcal Models, Molecular Molecular, Mutagenesis, Neisseria Protein Proteins, Recombinant Sequence Sequence, Serogroup Sialic Sialyltransferases Sites, bacterial_capsules meningitidis, {Site-Directed}, %N 5 %P 1258--1275 %R 10.1111/j.1365-2958.2007.05862.x %T Biochemical characterization of a Neisseria meningitidis polysialyltransferase reveals novel functional motifs in bacterial sialyltransferases %U http://www.ncbi.nlm.nih.gov/pubmed/17662040 %V 65 %X The extracellular polysaccharide capsule is an essential virulence factor of Neisseria meningitidis, a leading cause of severe bacterial meningitis and sepsis. Serogroup B strains, the primary disease causing isolates in Europe and America, are encapsulated in alpha-2,8 polysialic acid (polySia). The capsular polymer is synthesized from activated sialic acid by action of a membrane-associated polysialyltransferase (NmB-polyST). Here we present a comprehensive characterization of NmB-polyST. Different from earlier studies, we show that membrane association is not essential for enzyme functionality. Recombinant NmB-polyST was expressed, purified and shown to synthesize long polySia chains in a non-processive manner in vitro. Subsequent structure-function analyses of NmB-polyST based on refined sequence alignments allowed the identification of two functional motifs in bacterial sialyltransferases. Both (D/E-D/E-G and HP motif) are highly conserved among different sialyltransferase families with otherwise little or no sequence identity. Their functional importance for enzyme catalysis and CMP-Neu5Ac binding was demonstrated by mutational analysis of NmB-polyST and is emphasized by structural data available for the Pasteurella multocida sialyltransferase PmST1. Together our data are the first description of conserved functional elements in the highly diverse families of bacterial (poly)sialyltransferases and thus provide an advanced basis for understanding structure-function relations and for phylogenetic sorting of these important enzymes.

@article{freiberger_biochemical_2007, abstract = {The extracellular polysaccharide capsule is an essential virulence factor of Neisseria meningitidis, a leading cause of severe bacterial meningitis and sepsis. Serogroup B strains, the primary disease causing isolates in Europe and America, are encapsulated in alpha-2,8 polysialic acid {(polySia).} The capsular polymer is synthesized from activated sialic acid by action of a membrane-associated polysialyltransferase {(NmB-polyST).} Here we present a comprehensive characterization of {NmB-polyST.} Different from earlier studies, we show that membrane association is not essential for enzyme functionality. Recombinant {NmB-polyST} was expressed, purified and shown to synthesize long {polySia} chains in a non-processive manner in vitro. Subsequent structure-function analyses of {NmB-polyST} based on refined sequence alignments allowed the identification of two functional motifs in bacterial sialyltransferases. Both {(D/E-D/E-G} and {HP} motif) are highly conserved among different sialyltransferase families with otherwise little or no sequence identity. Their functional importance for enzyme catalysis and {CMP-Neu5Ac} binding was demonstrated by mutational analysis of {NmB-polyST} and is emphasized by structural data available for the Pasteurella multocida sialyltransferase {PmST1.} Together our data are the first description of conserved functional elements in the highly diverse families of bacterial (poly)sialyltransferases and thus provide an advanced basis for understanding structure-function relations and for phylogenetic sorting of these important enzymes.}, added-at = {2011-06-24T11:21:47.000+0200}, author = {Freiberger, Friedrich and Claus, Heike and GĂźnzel, Almut and {Oltmann-Norden}, Imke and Vionnet, Justine and MĂźhlenhoff, Martina and Vogel, Ulrich and Vann, Willie F and {Gerardy-Schahn}, Rita and Stummeyer, Katharina}, biburl = {https://www.bibsonomy.org/bibtex/2cec1abffbd379f82eed00938560484e3/ag_vogel}, doi = {10.1111/j.1365-2958.2007.05862.x}, interhash = {f462c03f2c8cc932c3cd72a75c4f0138}, intrahash = {cec1abffbd379f82eed00938560484e3}, issn = {{0950-382X}}, journal = {Molecular Microbiology}, keywords = {, Acid Acids, Adolescent, Alignment, Amino B, Bacterial Binding Child, Conformation, Data, Fusion Humans, Infections, Meningococcal Models, Molecular Molecular, Mutagenesis, Neisseria Protein Proteins, Recombinant Sequence Sequence, Serogroup Sialic Sialyltransferases Sites, bacterial_capsules meningitidis, {Site-Directed},}, month = sep, note = {{PMID:} 17662040}, number = 5, pages = {1258--1275}, timestamp = {2011-08-08T15:44:51.000+0200}, title = {Biochemical characterization of a Neisseria meningitidis polysialyltransferase reveals novel functional motifs in bacterial sialyltransferases}, url = {http://www.ncbi.nlm.nih.gov/pubmed/17662040}, volume = 65, year = 2007 }