Jianning Yin

We report improved whole-genome shotgun sequences for the genomes of indica and japonica rice, both with multimegabase contiguity, or almost 1,000-fold improvement over the drafts of 2002. Tested against a nonredundant collection of 19,079 full-length cDNAs, 97.7% of the genes are aligned, without fragmentation, to the mapped super-scaffolds of one or the other genome. We introduce a gene identification procedure for plants that does not rely on similarity to known genes to remove erroneous predictions resulting from transposable elements. Using the available EST data to adjust for residual errors in the predictions, the estimated gene count is at least 38,000-40,000. Only 2%-3% of the genes are unique to any one subspecies, comparable to the amount of sequence that might still be missing. Despite this lack of variation in gene content, there is enormous variation in the intergenic regions. At least a quarter of the two sequences could not be aligned, and where they could be aligned, single nucleotide polymorphism (SNP) rates varied from as little as 3.0 SNP/kb in the coding regions to 27.6 SNP/kb in the transposable elements. A more inclusive new approach for analyzing duplication history is introduced here. It reveals an ancient whole-genome duplication, a recent segmental duplication on Chromosomes 11 and 12, and massive ongoing individual gene duplications. We find 18 distinct pairs of duplicated segments that cover 65.7% of the genome; 17 of these pairs date back to a common time before the divergence of the grasses. More important, ongoing individual gene duplications provide a never-ending source of raw material for gene genesis and are major contributors to the differences between members of the grass family.

COP10 is a ubiquitin-conjugating enzyme variant (UEV), which is thought to act together with COP1, DET1, and the COP9 signalosome (CSN) in Arabidopsis to repress photomorphogenesis. Here, we demonstrate that COP10 interacts with ubiquitin-conjugating enzymes (E2s) in vivo, and can enhance their activity in vitro, an activity distinct from previous characterized UEVs such as MMS2 and UEV1. Furthermore, we show that COP10 forms a complex with UV-damaged DNA-binding protein 1a (DDB1a) and de-etiolated 1 (DET1), and physically interacts with COP1 and the CSN. Purified CDD (COP10, DDB1, DET1) complex also shows enhancement of E2 activity (UEA) similar to that observed with COP10 itself. Our data suggests that COP10, along with COP1 and the CSN, promotes the degradation of positive regulators of photomorphogenesis, such as the transcription factor HY5, via the ubiquitin/26S proteasome system. Thus, the CDD complex may act as a ubiquitylation-promoting factor to regulate photomorphogenesis.

A worldwide outbreak of severe acute respiratory syndrome (SARS) had been reported. Over 8439 SARS cases and 812 SARS-related deaths were reported to the World Health Organization from 32 countries around the world up to 5 July 2003. The mechanism of transmission of SARS-CoV has been limited only to close contacts with patients. Attention was focused on possible transmission by the sewage system because laboratory studies showed that patients excreted coronavirus RNA in their stools in Amoy Gardens in Hong Kong. To explore whether the stool of SARS patients or the sewage containing the stool of patients would transmit SARS-CoV or not, we used a style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing, as well as cell culture, semi-nested RT-PCR and sequencing of genes to detect and identify the viruses from sewage. There was no live SARS-CoV detected in the sewage in these assays. The nucleic acid of SARS-CoV was found in the sewage before disinfection from both hospitals by PCR. After disinfection, SARS-CoV RNA could be detected from some samples from the 309th Hospital of the Chinese People's Liberation Army, but not from Xiao Tang Shan Hospital after disinfection. In this study, we found that the virus can survive for 14 days in sewage at 4 degrees C, 2 days at 20 degrees C, and its RNA can be detected for 8 days though the virus had been inactivated. In conclusion, this study demonstrates that the RNA of SARS-CoV could be detected from the concentrates of sewage of both hospitals receiving SARS patients before disinfection and occasionally after disinfection though there was no live SARS-CoV; thus much attention should be paid to the treatment of stools of patients and the sewage of hospitals receiving SARS patients.

Snake venom is a complex mixture of proteins and peptides, and a number of studies have described the biological properties of several venomous proteins. Nevertheless, a complete proteomic profile of venom from any of the many species of snake is not available. Proteomics now makes it possible to globally identify proteins from a complex mixture. To assess the venom proteomic profiles from Naja naja atra and Agkistrodon halys, snakes common to southern China, we used a combination strategy, which included the following four different approaches: (i) shotgun digestion plus HPLC with ion-trap tandem MS, (ii) one-dimensional SDS/PAGE plus HPLC with tandem MS, (iii) gel filtration plus HPLC with tandem MS and (iv) gel filtration and 2DE (two-dimensional gel electrophoresis) plus MALDI-TOF (matrix-assisted laser desorption ionization-time-of-flight) MS. In the present paper, we report the novel identification of 124 and 74 proteins and peptides in cobra and viper venom respectively. Functional analysis based upon toxin categories reveals that, as expected, cobra venom has a high abundance of cardio- and neurotoxins, whereas viper venom contains a significant amount of haemotoxins and metalloproteinases. Although approx. 80% of gel spots from 2DE displayed high-quality MALDI-TOF-MS spectra, only 50% of these spots were confirmed to be venom proteins, which is more than likely to be a result of incomplete protein databases. Interestingly, these data suggest that post-translational modification may be a significant characteristic of venomous proteins.

BACKGROUND: The widespread threat of severe acute respiratory syndrome (SARS) to human life has spawned challenges to develop fast and accurate analytical methods for its early diagnosis and to create a safe antiviral vaccine for preventive use. Consequently, we thoroughly investigated the immunoreactivities with patient sera of a series of synthesized peptides from SARS-coronavirus structural proteins. METHODS: We synthesized 41 peptides ranging in size from 16 to 25 amino acid residues of relatively high hydrophilicity. The immunoreactivities of the peptides with SARS patient sera were determined by ELISA. RESULTS: Four epitopic sites, S599, M137, N66, and N371-404, located in the SARS-coronavirus S, M, and N proteins, respectively, were detected by screening synthesized peptides. Notably, N371 and N385, located at the COOH terminus of the N protein, inhibited binding of antibodies to SARS-coronavirus lysate and bound to antibodies in >94% of samples from SARS study patients. N385 had the highest affinity for forming peptide-antibody complexes with SARS serum. CONCLUSIONS: Five peptides from SARS structural proteins, especially two from the COOH terminus of the N protein, appear to be highly immunogenic and may be useful for serologic assays. The identification of these antigenic peptides contributes to the understanding of the immunogenicity and persistence of SARS coronavirus.