In this paper we report that the inclusion of heat-resistant RecA protein from a thermophilic bacteria, Thermus thermophilus, and its cofactor (ATP) in PCR effectively eliminates non-specific PCR products. The effect of RecA protein, which catalyzes pairing between homologous DNA molecules with great fidelity in genetic recombination, is due to its promotion of precise priming in PCR (i.e. priming at sites where the primer sequence is completely complementary to that of the target sequence). In addition, the RecA protein substantially reduces the primer concentration required for PCR. These experimental results have led to the realization of multiplex PCR, which involves PCR for multiple sites in the same reaction mixture. We were able to successfully perform multiplex PCR with over a dozen reactions without affecting the amplification pattern of the PCR products.

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Rolling circle amplification (RCA) of plasmid or genomic DNA using random hexamers and bacteriophage phi29 DNA polymerase has become increasingly popular in the amplification of template DNA in DNA sequencing. We have found that the mutant protein of single-stranded DNA binding protein (SSB) from Thermus thermophilus (Tth) HB8 enhances the efficiency of amplification of DNA templates. In addition, the TthSSB mutant protein increased the specificity of phi29 DNA polymerase. We have overexpressed the native and mutant forms of TthSSB protein in Escherichia coli and purified them to homogeneity. In vitro, these proteins were found to bind specifically to single-stranded DNA. Addition of TthSSB mutant protein to RCA halved the elongation time required for phi29 DNA polymerase to synthesize DNA fragments in RCA. Furthermore, the presence of the TthSSB mutant protein essentially eliminates nonspecific DNA products in RCA reactions.

IntroductionExtranodal lymphoma (ENL) in the muscles is a rare manifestation of non-Hodgkin lymphoma (NHL). The aim of this case report is to describe and evaluate the clinical presentation and important radiologic features of ENL affecting the musculoskeletal system.Presentation of caseWe present a 52-year-old female with a 3-week history of left gluteal pain. Computed tomography (CT) showed a non-uniformly early enhancing mass in the left gluteal muscle, the tumor demonstrating central necrosis and adjacent bone involvement. Fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET)/CT showed areas of increased 18F-FDG uptake in the left gluteal musculature, pelvic bones, para-aortic and mediastinal lymph nodes and both lungs. Histopathological examination showed a diffuse large B cell lymphoma (DLBCL). After 8 cycles of R-CHOP chemotherapy, the mass in the left gluteal muscle has completely disappearedDiscussionAlthough destructive tumor originating in the gluteal muscle with adjacent bone involvement is more common in soft tissue sarcoma, lymphoma should be regularly included in the differential diagnosis. While CT is a useful modality for assessing soft tissue masses, disruption and injury of the surrounding tissues, PET/CT fusion is superior for the detection of unexpected extranodal sites of disease, or for exclusion of disease in the presence of nonspecific extranodal CT findings.ConclusionA rapid growth pattern and destructive masses that invade adjacent structures on CT are key findings of DLBCL, and 18F-FDG PET/CT is a useful imaging modality to accurately determine the disease stage and disease aggressiveness of NHL.

A cDNA clone for the extrinsic 30 kDa protein (OEC30) of photosystem II in Euglena gracilis Z was isolated and characterized. The open reading frame of the cDNA encoded a polypeptide of 338 amino acids, which consisted of a long presequence of 93 amino acids and a mature polypeptide of 245 amino acids. Two hydrophobic domains were identified in the presequence, in contrast to the presence of a single hydrophobic domain in the presequence of the corresponding proteins from higher plants. At the N- and C-terminal regions, respectively, of the presequence, a signal-peptide-like sequence and a thylakoid-transfer domain were identified. The presence of a long and unique presequence in the precursor to OEC30 is probably related to the complexity of the intracellular processes required for the synthesis and/or transport of the protein in Euglena.