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ADP-glucose pyrophosphorylase catalyzes the first committed and rate-limiting step in starch biosynthesis in plants and glycogen biosynthesis in bacteria. It is the enzymatic site for regulation of storage polysaccharide accumulation in plants and bacteria, being allosterically activated or inhibited by metabolites of energy flux. We report the first atomic(More)
Branching enzyme catalyzes the formation of alpha-1,6 branch points in either glycogen or starch. We report the 2.3-A crystal structure of glycogen branching enzyme from Escherichia coli. The enzyme consists of three major domains, an NH(2)-terminal seven-stranded beta-sandwich domain, a COOH-terminal domain, and a central alpha/beta-barrel domain(More)
The structure of a phenylalanine aminomutase (TcPAM) from Taxus canadensis has been determined at 2.4 Å resolution. The active site of the TcPAM contains the signature 4-methylidene-1H-imidazol-5(4H)-one prosthesis, observed in all catalysts of the class I lyase-like family. This catalyst isomerizes (S)-α-phenylalanine to the (R)-β-isomer by exchange of the(More)
The Msx-1 homeodomain protein plays a crucial role in craniofacial, limb, and nervous system development. Homeodomain DNA-binding domains are comprised of 60 amino acids that show a high degree of evolutionary conservation. We have determined the structure of the Msx-1 homeodomain complexed to DNA at 2.2 A resolution. The structure has an unusually(More)
Human small nuclear RNA gene transcription by RNA polymerases II and III depends upon promoter recognition by the SNAPC general transcription factor. DNA binding by SNAPC involves direct DNA contacts by the SNAP190 subunit in cooperation with SNAP50 and SNAP43. The data presented herein shows that SNAP50 plays an important role in DNA binding by SNAPC(More)
We report a "running start, two-bond" protocol to analyze elongation by human RNA polymerase II (RNAP II). In this procedure, the running start allowed us to measure rapid rates of elongation and provided detailed insight into the RNAP II mechanism. Formation of two bonds was tracked to ensure that at least one translocation event was analyzed. By using(More)
The stereochemistry of a phenylalanine aminomutase (PAM) on the andrimid biosynthetic pathway in Pantoea agglomerans (Pa) is reported. PaPAM is a member of the 4-methylidene-1H-imidazol-5(4H)-one (MIO)-dependent family of catalysts and isomerizes (2S)-α-phenylalanine to (3S)-β-phenylalanine, which is the enantiomer of the product made by the mechanistically(More)
Escherichia coli glycogen synthase (EcGS, EC is a retaining glycosyltransferase (GT) that transfers glucose from adenosine diphosphate glucose to a glucan chain acceptor with retention of configuration at the anomeric carbon. EcGS belongs to the GT-B structural superfamily. Here we report several EcGS x-ray structures that together shed(More)
Protein-chromophore interactions are a central component of a wide variety of critical biological processes such as color vision and photosynthesis. To understand the fundamental elements that contribute to spectral tuning of a chromophore inside the protein cavity, we redesigned human cellular retinol binding protein II (hCRBPII) to fully encapsulate(More)
Porous nylon membranes modified with poly(acid) brushes and their derivatives can rapidly purify proteins via ion-exchange and metal-ion affinity interactions. Membranes containing poly(2-(methacryloyloxy)ethyl succinate) (poly(MES)) brushes bind 118 +/- 8 mg of lysozyme per cm(3) of membrane and facilitate purification of lysozyme from chicken egg white.(More)