The C-terminal domain of Tetrahymena thermophila telomerase holoenzyme protein p65 induces multiple structural changes in telomerase RNA.

The unique cellular activity of the telomerase reverse transcriptase ribonucleoprotein (RNP) requires proper assembly of protein and RNA components into a functional complex. In the ciliate model organism Tetrahymena thermophila, the La-domain protein p65 is required for in vivo assembly of telomerase. Single-molecule and biochemical studies have shown that p65 promotes efficient RNA assembly with the telomerase reverse transcriptase (TERT) protein, in part by inducing a bend in the conserved stem IV region of telomerase RNA (TER). The domain architecture of p65 consists of an N-terminal domain, a La-RRM motif, and a C-terminal domain (CTD). Using single-molecule Förster resonance energy transfer (smFRET), we demonstrate the p65(CTD) is necessary for the RNA remodeling activity of the protein and is sufficient to induce a substantial conformational change in stem IV of TER. Moreover, nuclease protection assays directly map the site of p65(CTD) interaction to stem IV and reveal that, in addition to bending stem IV, p65 binding reorganizes nucleotides that comprise the low-affinity TERT binding site within stem-loop IV.

Utilization survey of a rural creek fishery in central Alabama.

A one-year angler intercept survey was conducted on Choccolocco Creek, a rural, limited access tributary to the Coosa River in northeastern Alabama. The purpose of the survey was to collect data and information about the behaviors and fish consumption habits of the recreational anglers who fish there. Nine survey locations were included in the stratified sampling plan, and sampling occurred throughout daylight hours, on weekdays and weekends/holidays, during all four seasons of the year. Surveys were completed on a total of 101 survey days between June 28, 2008 and June 27, 2009.(6) Seventy-two anglers were observed fishing during the survey period, and 52 (72%) of those individuals agreed to participate in the survey. Based on the information collected by the survey clerks, the angler population fishes the Creek between 1 and 54 times per year, with an average frequency of seven trips per year. The average number of months fished was three months per year, with a range of one to nine months. Only 15% of the anglers who participated in the survey (eight individuals) had succeeded in catching fish by the end of their trips, and only four of those individuals (8%) had retained any of the fish they had caught for consumption. Reasons provided for not retaining fish were that they either only fished for sport, did not catch enough fish to eat, or the fish they caught were too small to keep. Because so few anglers used and harvested fish from the resource, fish consumption rates could not be determined with a high degree of confidence. However, from these limited data it was estimated that the three anglers for whom consumption rates could be estimated had annualized average daily fish consumption rates of 0.14, 0.44, and 7.9 grams per day (g/day). The majority of anglers traveled less than 10 miles to fish the Creek. It was estimated that a total population of 173 anglers use the Creek each year. The results of this survey indicated that Choccolocco Creek is a local fishery that is not heavily used by area residents.

Tandem cytochrome P450 monooxygenase genes and splice variants in the white rot fungus Phanerochaete chrysosporium: cloning, sequence analysis, and regulation of differential expression.

Phanerochaete chrysosporium, the model white rot fungus, uses P450 monooxygenation for oxidation of xenobiotic chemicals. To characterize its P450 systems, we have isolated two tandemly linked full-length P450 monooxygenase genes, pc-1 (2510bp) and pc-2 (2503bp). cDNA sequence and splice site analysis showed multiple small putative introns (35-82bp), 17 in pc-1 and 16 in pc-2. The deduced P450 proteins PC-1 (531 aa, MW 60,070) and PC-2 (538 aa, MW 61,765) showed 55% aa identity with each other and low relatedness (25-36%) with P450 gene families CYP52, CYP86, CYP4, and CYP3 decreasing in that order. Alternate splicing was identified for pc-1 transcription. Real-time quantitative RT-PCR analysis on 4-day cultures showed an elevated level of expression ( approximately 8-fold) of pc-1 in nutrient-limited (ligninolytic) as compared to nutrient-rich (non-ligninolytic) conditions. Interestingly, the pc-1 gene is expressible in both primary and secondary phases of growth with peak expression occurring with secondary metabolism.