Eukaryotes use small polypeptides of the ubiquitin [1,2] and Apg12 [3] families as tags to target proteins for degradation by the proteasome. Ubiquitin ligation is a multi-step process that involves at least three classes of enzymes [1]. The E1 enzymes first charge ubiquitin in an ATP-dependent manner to form an E1–ubiquitin thioester intermediate. This activated ubiquitin is transferred to the...

VVe searched a yeast genomic library fbr genes that conferred methylmercury resistance to yeast, Ymr258c was identified as a factor that conferred strong methylmercury resistance when overexpressed in budding yeast. Ymr258c is regarded as one of the F-box proteins, i.e,, component factors of the SkpllCullin!F-box protein (SCF) complex that functions as a ubiquitin ligase in the ubiquitin-protea...

We searched a yeast genomic library for genes that conferred methylmercury resistance to yeast. Ymr258c was identified as a factor that conferred strong methylmercury resistance when overexpressed in budding yeast. Ymr258c is regarded as one of the F-box proteins, i.e., component factors of the Skp1/Cullin/F-box protein (SCF) complex that functions as a ubiquitin ligase in the ubiquitin-proteas...

While some members of the ubiquitous DExD/H box family of proteins have RNA helicase activity in vitro, their roles in vivo remain virtually unknown. Here, we show that the function of an otherwise essential DEAD box protein, Prp28p, can be bypassed by mutations that alter either the protein U1-C or the U1 small nuclear RNA. Further analysis suggests that the conserved L13 residue in the U1-C p...

The transcriptional initiation sites of the chicken ribosomal protein L7a (rpL7a) gene have been determined and found to occur at three consecutive cytidine residues at the start of a polypyrimidine tract of 8 base pairs (bp). A comparative analysis of the 5' upstream regions of the mouse, human and chicken rpL7a genes identified two sequence elements (Box A and Box B) conserved over the 600 mi...

To explore the role of the HLH subdomain in bHLHZ proteins, we designed sets of minimalist proteins based on bHLHZ protein Max, bHLH/PAS protein Arnt and bZIP protein C/EBP. In the first, the Max bHLH and C/EBP leucine zipper were fused such that the leucine heptad repeats were not in register; therefore, the protein dimerization interface was disrupted. Max1bHLH-C/EBP showed little ability to ...

The orientation of the TATA box is thought to direct downstream transcription of eukaryotic genes by RNA polymerase II. However, the putative TATA box in the promoter of the bone sialoprotein (BSP) gene, which codes for a tissue-specific and developmentally regulated bone matrix protein, is inverted (5'-TTTATA-3') relative to the consensus TATA box sequence (5'-TATAAA-3') and is overlapped by a...