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dc.contributor.authorStafstrom, Joel P.
dc.contributor.authorStaehelin, L. Andrew
dc.date.accessioned2013-02-25T15:38:20Z
dc.date.available2013-02-25T15:38:20Z
dc.date.issued1986
dc.identifier.citationStafstrom JP, Staehelin LA (1986). Cross-linking patterns in salt-extractable extensin from carrot cell walls. Plant Physiol. 81:234-241.en_US
dc.identifier.issn0032-0889
dc.identifier.urihttp://commons.lib.niu.edu/handle/10843/13479
dc.identifier.urihttp://hdl.handle.net/10843/13479
dc.description.abstractExtensins are hydroxyproline-rich glycoproteins (HRGPs) found in the primary cell walls of dicots. Extensin monomers are secreted into the wall and covalently bound to each other, presumably by isodityrosine (IDT) cross-links, to form a rigid matrix. Expression of the extensin matrix is correlated with inhibition of cell elongation during normal development and with increased resistance to virulent pathogens. We have isolated extensin from carrot root tissue (Daucus carota L.) by published techniques and have used gel filtration chromatography to purify fractions enriched in monomers and oligomers. We refer to this protein as "extensin-l" to distinguish it from "extensin-2," a second extensin-like HRGP from carrot which we will describe later. We prepared extensin-1 for electron microscopy by shadowing it with platinum. Monomers are highly eloogated (a84 nanometers) and kinked at several sites. Kinks occur at all sites on molecules with nearly equal probability, but do not appear to occur at their ends. The distribution of kinks is similar to that of tyrosine-lysine-tyrosine sequences, which have been shown to be capable of forming intramolecular IDT cross-links, so we suggest that kinks are visible manifestations of intramolecular IDTs. Oligomers likely result from IDT cross-links between monomers, and may be regarded as transient precursors of the fully cross-linked matrix. Nearly 60% of cross-links involve the ends of molecules while the rest are scattered among internal sites. We discuss how the relative positions and proportions of intra- and intermolecular cross-links in extensin-1 may affect the structure, and in turn the function, of the extensin matrix.en_US
dc.language.isoen_USen_US
dc.publisherAmerican Society of Plant Biologistsen_US
dc.subjectextensinsen_US
dc.subjectHRGPsen_US
dc.titleCross-Linking Patterns in Salt-Extractable Extensin from Carrot Cell Wallsen_US
dc.typeArticleen_US
dc.contributor.departmentDepartment of Biological Sciences


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