The sulfolipid sulfoquinovosyldiacylglycerol is a component of plant photosynthetic membranes and represents one of the few naturally occurring sulfonic acids with detergent properties. Sulfolipid biosynthesis involves the transfer of sulfoquinovose, a 6-deoxy-6-sulfoglucose, from UDP-sulfoquinovose to diacylglycerol. The formation of the sulfonic acid precursor, UDP-sulfoquinovose, from UDP-gl...

This document describes the Lightweight User Datagram Protocol (UDPLite), which is similar to the User Datagram Protocol (UDP) (RFC 768), but can also serve applications in error-prone network environments that prefer to have partially damaged payloads delivered rather than discarded. If this feature is not used, UDP-Lite is semantically identical to UDP. Larzon, et al. Standards Track [Page 1]...

We studied the UDP-glucose pyrophosphorylase (galU) and UDP-galactose epimerase (galE) genes of Lactococcus lactis MG1363 to investigate their involvement in biosynthesis of UDP-glucose and UDP-galactose, which are precursors of glucose- and galactose-containing exopolysaccharides (EPS) in L. lactis. The lactococcal galU gene was identified by a PCR approach using degenerate primers and was fou...

UDP-galactose 4-epimerase catalyzes the interconversion of UDP-galactose and UDP-glucose during normal galactose metabolism. One of the key structural features in the proposed reaction mechanism for the enzyme is the rotation of a 4'-ketopyranose intermediate within the active site pocket. Recently, the three-dimensional structure of the human enzyme with bound NADH and UDP-glucose was determin...

Syntheses of several plant polysaccharides involving in vitro glycosyl transfer from nucleotide sugars have now been reported using the enzymes present in particulate preparations from plant tissues. Such syntheses include starch from UDP-D-glucose1 or ADP-D-glucose,2 pectin from UDP-D-galacturonic acid,3 callose from UDP-D-glucose,4 and cellulose from GDP-D-glucose5 or UDP-D-glucose.6 Indirect...

This document specifies a Management Information Base (MIB) module for the Lightweight User Datagram Protocol (UDP-Lite). It defines a set of new MIB objects to characterise the behaviour and performance of transport layer endpoints deploying UDP-Lite. UDP-Lite resembles UDP, but differs from the semantics of UDP by the addition of a single option. This adds the capability for variable-length d...

The formation of heparin-precursor polysaccharide (N-acetylheparosan) was studied with a mouse mastocytoma microsomal fraction. Incubation of this fraction with UDP-[3H]GlcA and UDP-GlcNAc yielded labelled macromolecules that could be depolymerized, apparently to single polysaccharide chains, by alkali treatment, and thus were assumed to be proteoglycans. Label from UDP-[3H]GlcA (approx. 3 micr...

UDP-galactose 4-epimerase from Escherichia coli catalyzes the interconversion of UDP-glucose and UDP-galactose. In recent years, the enzyme has been the subject of intensive investigation due in part to its ability to facilitate nonstereospecific hydride transfer between beta-NADH and a 4-keto hexopyranose intermediate. The first molecular model of the epimerase from E. coli was solved to 2.5 A...

The cell wall polysaccharide of Streptococcus gordonii 38 functions as a coaggregation receptor for surface adhesins on other members of the oral biofilm community. The structure of this receptor polysaccharide (RPS) is defined by a heptasaccharide repeat that includes a GalNAcbeta1-->3Gal-containing recognition motif. The same RPS has now been identified from S. gordonii AT, a partially sequen...

With the rapid development of network, multimedia is largely applied in several areas, and it needs high bandwidth for network to transmit multimedia. At present UDP is always applied as lower layer for transmitting multimedia because it has high-speed transfer rate. However, UDP loses more packets under the condition of insufficient network bandwidth. Therefore in this paper we add the control...