NRMT1 is an N-terminal methyltransferase that methylates histone CENP-A as well as nonhistone substrates. Here, we report the crystal structure of human NRMT1 bound to CENP-A peptide at 1.3 Å. NRMT1 adopts a core methyltransferase fold that resembles DOT1L and PRMT but not SET domain family histone methyltransferases. Key substrate recognition and catalytic residues were identified by mutagenesis studies. Histone peptide profiling revealed that human NRMT1 is highly selective to human CENP-A and fruit fly H2B, which share a common "X aaPro-Lys/Arg" motif. These results, along with a 1.5 Å costructure of human NRMT1 bound to the fruit fly H2B peptide, underscore the importance of the NRMT1 recognition motif.

BackgroundThe baseline data pertaining to the national epidemiological survey of infectious keratitis remain scarce in China, and currently there is no corneal blindness control strategy developed by the nation.MethodsGeographically defined cluster sampling was used to randomly select a cross-section of residents from representative urban and rural populations in Hubei Province. Participants were selected from village registers, followed by door-to-door household visits. The assessment items included a structured interview, visual acuity testing, external eye examination, and anterior segment examination using slit lamp. Causes and sequelae of corneal disease were identified according to uniform customized protocol.ResultsThe prevalence of presenting corneal diseases was 0.8% (211/26 305), while the prevalence of infectious keratitis was 0.148% (39/26 305). The prevalences of viral, bacterial, and fungal keratitis were 0.065, 0.068, and 0.015%, respectively. There were no significant differences found between the prevalences of viral (accounting for 43.6%) and bacterial (accounting for 46.2%) corneal ulcers. cases of Acanthamoeba keratitis were not found. Infectious keratitis was the leading cause of corneal blindness (85.7%), and the prevalence of blindness in at least one eye resulting from infected corneas was 0.091% (95% CI: 0.067-0.127%).ConclusionsViral and bacterial mechanisms constitute the most important risk factors for infectious corneal ulcers in Central China. To reduce the rate and severity of infectious keratitis, he public health care policy should be focused on designing cost-effective strategies and operational programs for the prevention and prompt treatment of infectious corneal ulcers.

The in vitro effect of extracted fractions of Cordyceps sinensis (CS) mycelium on hCG-treated testosterone production from purified normal mouse Leydig cells was examined. Different fractions extracted from CS (F1-water soluble polysaccharide, F2-water soluble protein and F3-poorly water soluble polysaccharide, and protein) were added to Leydig cells with hCG, and the production of testosterone was determined by radioimmunoassay (RIA). Testosterone productions stimulated by hCG in mouse Leydig cells were suppressed by F2 at 10 mg=ml and F3 at doses from 3 to 10 mg=ml, respectively. F2 and F3 at 10 mg=ml did inhibit dbcAMP-stimulated testosterone productions which indicated that F2 and F3 might affect steroidogenesis at the site after the formation of cyclic AMP. Finally, cycloheximide inhibited F2-and F3-treated mouse Leydig cell testosterone production.

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