Portland Press Ltd.

1. The RNA-dependent RNA polymerase from Halobacterium cutirubrum was purified to electrophoretic homogeneity. 2. It requires a single-stranded molecule of RNA or polyribonucleotide as template. 3. Nearest-neighbour analyses of the products formed on random poly(A,U) or alternating poly(A-U) templates and base analysis of the product of synthesis directed by wheat-germ RNA prove that the template is copied accurately. 4. The enzyme initiates new chains with purine ribonucleoside triphosphates. 5. Sucrose-density-gradient analysis of the product indicates that it has a size distribution similar to that of the template. 6. Preliminary amino acid analysis of the RNA-dependent polymerase shows that it contains much less serine than either of the subunits of H. cutirubrum DNA-dependent RNA polymerase. 7. The RNA-dependent enzyme is unable to substitute for either subunit of the DNA-dependent polymerase, and both the latter are devoid of RNA-dependent activity.

1. Crude extracts of the extreme halophile Halobacterium cutirubrum contain separable DNA-dependent and RNA-dependent RNA polymerases. 2. The RNA-dependent enzyme has been purified about 2800-fold. 3. It requires RNA, preferably of high molecular weight, and all four ribonucleoside triphosphates to incorporate 14C-labelled nucleoside triphosphate into an acid-insoluble, ribonuclease-sensitive product. 4. Both the stability and activity of the RNA polymerase are relatively insensitive to changes in potassium chloride or sodium chloride concentration, but incorporation is stimulated by both Mg2+ and Mn2+. 5. The molecular weight of the enzyme is about 17000–18000.

Incubation of tyrosine with the RNA from brome-mosaic-virus under conditions favourable for aminoacylation of tRNA resulted in binding of tyrosine to the viral RNA. Sucrose-density-gradient centrifugation showed that tyrosine binds to three and probably to all four of the viral RNA components. The bound amino acid was readily released in mild alkaline solutions. Of 20 amino acids tested, only tyrosine was found to bind. The maximum extent of binding observed was 0.58mol of tyrosine/mol of brome-mosaic-virus RNA.

1. Cấu trúc phosphatidylglucose được đề xuất trước đây (Smith & Henrikson, 1965) cho phospholipid chứa glucose từ Acholeplasma laidlawii là không chính xác. 2. Cấu trúc hiện tại được đề xuất là 3-(sn-glycerol-3-phosphoryl-6′-[O-α-d-glucopyranosyl-(1&2)-O-α-d-glucopyranosyl])-sn-1,2-diglyceride, một loại lipid vi khuẩn mới. 3. Việc khử axit béo của lipid đã cho ra một este phosphate hòa tan trong nước duy nhất có thể phân biệt được trên sắc ký với các mẫu phosphorylglycerol glucosyl tổng hợp. 4. Thủy phân lipid bằng kiềm đã tạo ra một hỗn hợp axit béo, glycerol 2-phosphate, sn-glycerol 3-phosphate và O-α-d-glucopyranosyl-(1&2)-O-α-d-glucopyranosyl-(1&1)-d-glycerol. 5. Lipid không bị ảnh hưởng khi được ủ với phospholipase A, C và D. 6. Diglucosyl diglyceride đã được tách ra sau khi điều trị lipid với 60% HF, xác định vị trí của các dư lượng axit béo. 7. Nghiên cứu oxi hóa periodat cho thấy rằng sn-glycerol 3-phosphate đã được este hóa với nhóm hydroxyl thứ 6 của một trong các dư lượng glucose trong diglucosyl diglyceride.

Mitochondria isolated from the flight muscle of the southern armyworm moth, Prodenia eridania, can oxidize palmitate+malate very rapidly. Added carnitine had no effect on the rate of oxidation of palmitate+malate by flight-muscle mitochondria from two species of moths, and carnitine palmitoyltransferase could not be detected in Prodenia by direct assay. Palmitoylcarnitine was not oxidized by moth mitochondria, but when added in low concentrations it reversibly suppressed the oxidation of palmitate. The evidence indicates that carnitine is not involved in fatty acid degradation by moth flight muscle. Added thiols, including CoA, also suppressed palmitate+malate oxidation. An ATP-dependent fatty acyl-CoA synthetase is present in moth mitochondria.