Important advances have recently been made in the chemistry of the lower oxides of sulfur, both in the preparative sphere and by the application of modern physical methods of in-vestigation. In this paper the knowledge gained to date on the compounds SO, S202, s20, S203, and the polysuljiur oxides is reviewed and critically appraised. DefinitionIn the present paper, the term "lower o x i d e s of s u lfur" refers to oxides in which the oxidation number z of suIfur is < 2. Thus, although S2O3 is discussed briefly, it does not belong to this group, particularly since the sulfur in this compound is evidently present in two very different oxidation states. However, the term does encompass the oxides SO, S 2 0 2 , S 2 0 , and the polysulfur oxides of general formula (S,O), in which n > 2. According to their properties, compounds containing hydrogen in addition to sulfur and oxygen should be grouped together with the polysulfur oxides. These compounds will be referred to as polysulfane oxides. SO (likeS2) is present in an appreciable concentration only at high temperatures. The enthalpy of formation of sulfur monoxide is found by investigation of equilibria such as those shown in Equations (b) and (c) [9, lo]. 2 SO2 7 ' SO --SO3 at 1500°C (b) AH: = +48.6 kcal/mole of SO SOz f 1/2 Sz T' 2 SO at 1250 "C (c) AH:+58.3 kcal/mole of SO2

Intranuclear B-capsids from cytomegalovirus (strain Colburn)-infected cells contain an abundant 37-kDa assembly protein, thought to be involved in capsid formation, and three minor protein constituents (i.e., 45, 39, and 38 kDa) that are immunologically and structurally related to the assembly protein. In the experiments reported here, antisera produced against synthetic peptides were used in conjunction with chemical protein cleavage to examine the structural relationship of these proteins in more detail. Results of these experiments verify that the carboxyl end of the 39-kDa assembly protein precursor is lost during maturation and suggest that the 38-kDa protein may be a processing intermediate. It is shown that the 45-kDa protein is coterminal with the mature assembly protein at its carboxyl end but differs by a predicted 115-amino-acid extension at its amino terminus. In addition, evidence is presented that the 45-kDa protein has a 48-kDa precursor and a 47-kDa putative processing intermediate which have the same carboxy-terminal sequences and undergo the same maturational events as those of the assembly protein. A working model considering the structural relationship of these proteins is presented.

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cDNA complementary to the 3'-terminal half of RNA 1 of wheat spindle streak mosaic virus (WSSMV) from Southern France has been cloned and sequenced. One large open reading frame (ORF) of 4410 nucleotides and a nontranslated region (NTR) of 213 nucleotides at the 3'-end excluding the poly(A)-tail were found. Because of the amino acid sequence homology to the polyprotein of barley yellow mosaic virus (BaYMV) RNA 1, the encoded polyprotein of the sequenced region of WSSMV is supposed to comprise the C-terminal part of the putative cytoplasmic inclusion (CI) protein, the nuclear inclusion a (NIa) proteinase, the (NIb) RNA-polymerase and the capsid protein. The first 19 N-terminal amino acids of the capsid protein were determined by direct sequencing of proteins of purified WSSMV particles and confirmed this hypothesis. The deduced capsid protein has 294 amino acids and shows 74% identity with the BaYMV capsid protein sequence. This high sequence homology with BaYMV, in addition to the significant identities with barley mild mosaic virus (BaMMV, 35%) and its marginal homology to capsid protein sequences of aphid and mite-borne potyviruses (22-24%), supports the classification of WSSMV as a distinct member of the genus Baymovirus, family Potyviridae.