Other Biochemistry, Biophysics, and Structural Biology Commons^™

Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden

Biochemistry and Microbiology

Morphological alterations have been shown to occur in Drosophila melanogaster when function of Hsp90 (heat shock 0-kDa protein 1α, encoded by Hsp83) is compromised during development1. Genetic selection maintains the altered phenotypes in subsequent generations1. Recent experiments have shown, however, that phenotypic variation still occurs in nearly isogenic recombinant inbred strains of Arabidopsis thaliana2. Using a sensitized isogenic D. melanogaster strain, iso-KrIf-1, we confirm this finding and present evidence supporting an epigenetic mechanism for Hsp90’s capacitor function, whereby reduced activity of Hsp90 induces a heritably altered chromatin state. The altered chromatin state is evidenced by ectopic expression …

The Atp:Co(I)Rrinoid Adenosyltransferase (Coba) Enzyme Of Salmonella Enterica Requires The 2'-Oh Group Of Atp For Function And Yields Inorganic Triphosphate As Its Reaction Byproduct, Maris V. Fonseca, Nicole R. Buan, Alexander R. Horswill, Ivan Rayment, Jorge C. Escalante-Semerena

Department of Biochemistry: Faculty Publications

The specificity of the ATP:corrinoid adenosyltransferase (CobA) enzyme of Salmonella enterica serovar Typhimurium LT2 for its nucleotide substrate was tested using ATP analogs and alternative nucleotide donors. The enzyme showed broad specificity for the nucleotide base and required the 2’-OH group of the ribosyl moiety of ATP for activity. ³¹P NMR spectroscopy was used to identify inorganic triphosphate (PPP_i) as the byproduct of the reaction catalyzed by the CobA enzyme. Cleavage of triphosphate into pyrophosphate and orthophosphate did not occur, indicating that triphosphate cleavage was not required for release of the adenosylcorrinoid product. Triphosphate was a strong …

Vectorial Acylation In Saccharomyces Cerevisiae, Zhiying Zou, Fumin Tong, Nils J. Færgeman, Claus Børsting, Paul N. Black, Concetta Dirusso

Department of Biochemistry: Faculty Publications

In Saccharomyces cerevisiae Fat1p and fatty acyl-CoA synthetase (FACS) are hypothesized to couple import and activation of exogenous fatty acids by a process called vectorial acylation. Molecular genetic and biochemical studies were used to define further the functional and physical interactions between these proteins. Multicopy extragenic suppressors were selected in strains carrying deletions in FAA1 and FAA4 or FAA1 and FAT1. Each strain is unable to grow under synthetic lethal conditions when exogenous long-chain fatty acids are required, and neither strain accumulates the fluorescent long-chain fatty acid C₁-BODIPY-C₁₂ indicating a fatty acid transport defect. By using these …

Serotyping Group B Streptococci In A Small Community Hospital: An Analysis Of Distribution And Site Of Isolation, Jennifer M. Smith, Jason A. Rexroth, David G. Chaffin, Susan H. Jackman

Biochemistry and Microbiology

Objective: To determine the prevalence and site of isolation of different serotypes of group B streptococcus (GBS) colonization or infection at a small community hospital.

Methods: GBS isolates were obtained from a small community hospital and were then serotyped as la, Ib, II, III, IV, V or non-typeable. Hospital records were reviewed for patient sex, age and pregnancy status as well as the site of GBS isolation.

Results: GBS serotypes Ia, III and V were most common and accounted for over 60% of the total number of isolates. Serotype Ia was most prevalent in reproductive-age females, while serotypes V and …

Murine Epidermal Cell Antigen (Skn)-Directed Autoimmunity Induced By Transfer Of Cd4+ T Cells, Susan H. Jackman, Shivaleela Keerthy, Giselle Perry

Biochemistry and Microbiology

While pathogenic T cells have been identified for several diseases with epithelial cell damage, an autoimmune T cell-mediated response targeted against a known keratinocyte antigen has not been reported. Previously we described an autoimmune response directed to the mouse epidermal cell antigens, Skn. For our murine model, primed Skn-immune lymphocytes are adoptively transferred to recipients, which develop lesions at the site of mild skin trauma. In this study we investigated the nature of the autoimmune component of the Skn response. A time-course study demonstrated a relationship between the number of primed Sknimmune cells injected and the severity of skin lesions …

The Atp:Co(I)Rrinoid Adenosyltransferase (Coba) Enzyme Of Salmonella Enterica Requires The 2’-Oh Group Of Atp For Function And Yields Inorganic Triphosphate As Its Reaction Byproduct, Maris V. Fonseca, Nicole R. Baun, Alexander R. Horswill, Ivan Rayment, Jorge C. Escalante-Semerena

Department of Biochemistry: Faculty Publications

The specificity of the ATP:corrinoid adenosyltransferase

(CobA) enzyme of Salmonella enterica serovar

Typhimurium LT2 for its nucleotide substrate was

tested using ATP analogs and alternative nucleotide donors.

The enzyme showed broad specificity for the nucleotide

base and required the 2’-OH group of the ribosyl

moiety of ATP for activity. ³¹P NMR spectroscopy

was used to identify inorganic triphosphate (PPP_i) as

the byproduct of the reaction catalyzed by the CobA

enzyme. Cleavage of triphosphate into pyrophosphate

and orthophosphate did not occur, indicating that

triphosphate cleavage was not required for release of

the adenosylcorrinoid product. Triphosphate was …