Funds are requested for an X-ray data collection system for macromolecular crystal structure determination. The instrument is the R-AXIS II imaging plate system, which includes a rotating anode X-ray generator, focusing mirrors, and a controlling computer. The new instrument will be located in Stanley Hall at the University of California, Berkeley, and will be shared by three research groups which- use X-ray crystallography as a primary research tool. Currently, the three research groups share one X-ray area detector, which is used full time, and the backlog of data collection limits progress. The three groups have a broad range of research interests. The proteins and peptides under investigation differ significantly in size and biological function. Prof. Alber asks general questions about protein folding, stability, and intra- and intermolecular protein interactions. Model systems used to test these questions include coiled-coils, T4 lysozyme, ATCase, and transcriptional accessory proteins. Prof. Nelson studies DNA binding proteins and protein-DNA interactions. Crystals of the DNA binding domain of the heat shock transcription factor diffract X-rays to at least 0.9 resolution, making this the highest resolution structure for which mutants are readily obtained. Prof. Stevens studies proteins involved in neurotransmission. Proteins under study include: two proteins involved in catecholamine biosynthesis, tyrosine hydroxylase and dopamine monoxygenase; neuroreceptors, such as human 2-adrenergic receptor, fish olfactory receptor, and yeast factor receptor; and the botulinum neurotoxin. In addition, to the individual research interests of the three groups, collaborative crystallographic projects have been initiated with other faculty at Berkeley. Clearly, an additional instrument will allow significant progress to made on a wide range of crystallographic studies. In addition to supporting the research efforts of these three groups, this instrument will have a train ing function. Between the three groups, there are 4 post-doctoral fellows, 14 graduate students, and 4 undergraduates who are pursuing crystallographic projects. The size of the joint group is expected to grow by 6 more students and fellows within the next year.
