Fighting HIV/AIDS

Fighting HIV/AIDS structure of a transcription initiation complex is solved, and we can visualize the interacting components. Gal1 also gives the authors a way to segue into the concept Staying Alive of sequential recruiting. Thus, the initial activators of Onward to higher eukaryotes and a variety of regulatory pathways. To show directly that mechanisms de-Less than a decade after the fall of apartheid, South scribed in yeast are functional in higher organisms, the Africa is faced with the largest and most rapidly growing authors point out that Gal4 functions quite well as an HIV/AIDS epidemic in Africa and in the world. In South activator in Drosophila. The differences between yeast Africa, over 4.7 million people, or one in four adults, are and multicellular organisms are also described. For ex-currently thought to be living with HIV/AIDS. At present, ample, the proportion of histone that is acetylated in this number is higher than in any other country in the mammals is lower than in yeast, but acetylation is con-world and is expected to double over the next decade. centrated near active genes. A regulatory mechanism The salient characteristics of the epidemic are three-that allows polymerase stalled a short distance from fold: (1) Explosive in nature; most information has been the promoter to continue transcription in response to based upon seroprevalence studies in antenatal clinics. regulatory factors may be unique to higher organisms. These show steeply rising rates of HIV infection from And DNA methylation is not found in yeast, but serves less than 1% in 1991 to over 30% in 2000. In the most an important regulatory role in more advanced eukary-heavily affected province, KwaZuluNatal, the latest fig-otes. In a final burst of synthesis, Ptashne and Gann ures show a prevalence rate of 36% among antenatal clinic attendees and an annual incidence rate of 20%. propose that signal transduction, RNA splicing, cell cy-(2) Predominant heterosexual transmission with higher cle control, and proteolysis can all be understood by rates and lower age among women; estimates indicate the principle of recruitment. that 60% of infections are in women and the median So what is the value of this book? It explains complex infection age among women is 22 years, whereas it is biological reactions in terms of a few simple principles. 30 years among men, an indication of a pattern of older Even if recruitment is often a heuristic device, it does men having …