Limits...
Structure of the K12 capsule containing 5,7-di-N-acetylacinetaminic acid from Acinetobacter baumannii isolate D36.

Kenyon JJ, Marzaioli AM, Hall RM, De Castro C - Glycobiology (2015)

Bottom Line: This matched the sugar composition of the K12 capsule and the genetic content of the KL12 capsule gene cluster reported previously.D-FucpNAc was predicted to be the substrate for the initiating transferase, ItrB3, with the Wzy polymerase making a α-D-FucpNAc-(1 → 3)-D-GalpNAc linkage between the repeat units.The three glycosyltransferases encoded by KL12 are all retaining glycosyltransferases and were predicted to form specific linkages between the sugars in the K12 repeat unit.

View Article: PubMed Central - PubMed

Affiliation: School of Molecular Bioscience, The University of Sydney, Sydney, NSW 2006, Australia.

No MeSH data available.


(600 MHz, 45°C) Expansion of the (A) TOCSY and (B) NOESY spectra of dCPS from A. baumannii D36. Cross-peaks attribution is indicated nearby the corresponding density, those barred should belong to CPS still substituted with Aci5Ac7Ac. A4B1 and B5A1 NOEs could not be attributed unequivocally because of the superimposition with other proton signals, indeed the possibility of intra-residue effect due to spin diffusion along with NOEs given between sugars belonging to different repeating units could not be ruled out. These two possibilities are indicated with “Ci” or “Ai” meaning intra-residue or inter-repeating units NOEs of (C) or (A) residues, respectively.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4487303&req=5

CWV028F4: (600 MHz, 45°C) Expansion of the (A) TOCSY and (B) NOESY spectra of dCPS from A. baumannii D36. Cross-peaks attribution is indicated nearby the corresponding density, those barred should belong to CPS still substituted with Aci5Ac7Ac. A4B1 and B5A1 NOEs could not be attributed unequivocally because of the superimposition with other proton signals, indeed the possibility of intra-residue effect due to spin diffusion along with NOEs given between sugars belonging to different repeating units could not be ruled out. These two possibilities are indicated with “Ci” or “Ai” meaning intra-residue or inter-repeating units NOEs of (C) or (A) residues, respectively.

Mentions: Analysis of the 2D spectra of dCPS permitted the assignment of all proton and carbon chemical shifts (Table I, structure in Figure 3). The anomeric proton at 5.01 ppm was assigned to residue A: this proton presented only three TOCSY correlations (Figure 4A), due to the H-4/H-5 coupling, characteristic of galacto configured sugars. Proton and carbon chemical shift of C-2 underlined that it was N-acetylated. H-5 (3.93 ppm) was identified in the Nuclear Overhauser Effect Spectroscopy (NOESY) spectrum by its cross-peak with H-4, whereas H-6s (3.76 ppm) were detected in the COSY spectrum via H-6/H-5 cross-peak. Therefore, A was an N-acetyl α-galactosamine and the low-field displacement of its C-3 signal (73.8 ppm) (Figure 5) confirmed glycosylation at this position, in agreement with methylation analyses.Table I.


Structure of the K12 capsule containing 5,7-di-N-acetylacinetaminic acid from Acinetobacter baumannii isolate D36.

Kenyon JJ, Marzaioli AM, Hall RM, De Castro C - Glycobiology (2015)

(600 MHz, 45°C) Expansion of the (A) TOCSY and (B) NOESY spectra of dCPS from A. baumannii D36. Cross-peaks attribution is indicated nearby the corresponding density, those barred should belong to CPS still substituted with Aci5Ac7Ac. A4B1 and B5A1 NOEs could not be attributed unequivocally because of the superimposition with other proton signals, indeed the possibility of intra-residue effect due to spin diffusion along with NOEs given between sugars belonging to different repeating units could not be ruled out. These two possibilities are indicated with “Ci” or “Ai” meaning intra-residue or inter-repeating units NOEs of (C) or (A) residues, respectively.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4487303&req=5

CWV028F4: (600 MHz, 45°C) Expansion of the (A) TOCSY and (B) NOESY spectra of dCPS from A. baumannii D36. Cross-peaks attribution is indicated nearby the corresponding density, those barred should belong to CPS still substituted with Aci5Ac7Ac. A4B1 and B5A1 NOEs could not be attributed unequivocally because of the superimposition with other proton signals, indeed the possibility of intra-residue effect due to spin diffusion along with NOEs given between sugars belonging to different repeating units could not be ruled out. These two possibilities are indicated with “Ci” or “Ai” meaning intra-residue or inter-repeating units NOEs of (C) or (A) residues, respectively.
Mentions: Analysis of the 2D spectra of dCPS permitted the assignment of all proton and carbon chemical shifts (Table I, structure in Figure 3). The anomeric proton at 5.01 ppm was assigned to residue A: this proton presented only three TOCSY correlations (Figure 4A), due to the H-4/H-5 coupling, characteristic of galacto configured sugars. Proton and carbon chemical shift of C-2 underlined that it was N-acetylated. H-5 (3.93 ppm) was identified in the Nuclear Overhauser Effect Spectroscopy (NOESY) spectrum by its cross-peak with H-4, whereas H-6s (3.76 ppm) were detected in the COSY spectrum via H-6/H-5 cross-peak. Therefore, A was an N-acetyl α-galactosamine and the low-field displacement of its C-3 signal (73.8 ppm) (Figure 5) confirmed glycosylation at this position, in agreement with methylation analyses.Table I.

Bottom Line: This matched the sugar composition of the K12 capsule and the genetic content of the KL12 capsule gene cluster reported previously.D-FucpNAc was predicted to be the substrate for the initiating transferase, ItrB3, with the Wzy polymerase making a α-D-FucpNAc-(1 → 3)-D-GalpNAc linkage between the repeat units.The three glycosyltransferases encoded by KL12 are all retaining glycosyltransferases and were predicted to form specific linkages between the sugars in the K12 repeat unit.

View Article: PubMed Central - PubMed

Affiliation: School of Molecular Bioscience, The University of Sydney, Sydney, NSW 2006, Australia.

No MeSH data available.