The structure of cell wall alpha-glucan from fission yeast.
Morphology and structural integrity of fungal cells depend on cell wall polysaccharides. The chemical structure and biosynthesis of two types of these polysaccharides, chitin and (1-->3)-beta-glucan, have been studied extensively, whereas little is known about alpha-glucan. Here we describe the chemical structure of alpha-glucan isolated from wild-type and mutant cell walls of the fission yeast Schizosaccharomyces pombe. Wild-type alpha-glucan was found to consist of a single population of linear glucose polymers, approximately 260 residues in length. These glucose polymers were composed of two interconnected linear chains, each consisting of approximately 120 (1-->3)-linked alpha-d-glucose residues and some (1-->4)-linked alpha-D-glucose residues at the reducing end. By contrast, alpha-glucan of an alpha-glucan synthase mutant with an aberrant cell morphology and reduced alpha-glucan levels consisted of a single chain only. We propose that alpha-glucan biosynthesis involves an ordered series of events, whereby two alpha-glucan chains are coupled to create mature cell wall alpha-glucan. This mature form of cell wall alpha-glucan is essential for fission-yeast morphogenesis.
Bijvoet Center, Department of Bio-Organic Chemistry, Section of Glycoscience and Biocatalysis, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Christian H
CH
Grün
Frans
F
Hochstenbach
Bruno M
BM
Humbel
Arie J
AJ
Verkleij
J Hans
JH
Sietsma
Frans M
FM
Klis
Johannis P
JP
Kamerling
Johannes F G
JF
Vliegenthart
D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D005936:Glucans / Q000737:chemistry* / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D012568:Schizosaccharomyces / Q000737:chemistry* / Q000166:cytology* / Q000235:genetics / Q000648:ultrastructure
D005936:Glucans; D005947:Glucose