Neurospora comparisons

The data presented in Table 3, which includes the amino acid composition of baker s yeast and Candida krusei cytochrome c for comparison, show that Ustilago and Neurospora cytochrome c contain the same number of total residues. In seven instances, the number of residues of a particular amino acid/mole are identical. Thus, even in the absence of a sequence for the Ustilago cytochrome it can be concluded that this protein, unlike the siderochromes, has suffered little alteration in the progression from the Ascomycetes to the Basidiomycetes. This can be ascribed to the varying function of the two types of molecules. Cytochrome c must fit into a relatively specific slot bounded by a reductase and an oxidase and it has hence evolved much more slowly than the more freely acting transport agents where the specificity constraints are less demanding. 

Sequence comparisons show that the CuA-binding sites of M-Hc and the tyrosinases did not develop by gene duplication of CuB, but by the addition of a new copper-binding structure, possibly of a totally new copper protein. In this, M-Hc and most tyrosinases differ from the tyrosinase of Neurospora [34,247],... 

Fig. 19. Alignment of homospermidine synthase (HSS) amino acid sequence from Senecio ver-nalis (Sv) in comparison to deoxyhypusine synthase amino acid sequences from six different species. Sv, Senecio vernalis Nt, Nicotiana tabacumi Hs, Homo sapiens Sc, Saccharomyces cerevisiae Nc, Neurospora crassa Mj, Methanococcus jannaschii. Black boxes denote identical amino acid residues in all seven sequences, framed boxes conservative replacement...

From a comparison of the growth response of Neurospora to kynurenic and xanthurenic acids with that of a number of nicotinic acid derivatives, it was concluded that the pyridine ring of nicotinic acid is not formed by kynurenine first being converted to kynurenic acid or xanthurenic acid, and this in turn being followed by the oxidation of the benzene ring moiety to yield nicotinic acid as a residium. ... 

At the same time that the early studies mentioned above were carried out, it was shown by Loring and Pierce that certain Neurospora mutants utilized uracil and cytosine very poorly in comparison to uridine (uracil riboside) and cytidine (cytosine riboside). These observations led to the suggestion that free pyrimidines were not normal intermediates in nucleic acid biosynthesis. Similar conclusions have been reached by Fries with pyrimidine-deficient strains of the mold Ophiostoma muUiannulatum. ... 

FIGURE 124.2 Primary sequence comparison of the microbial rhodopsins. (Hs Halobacterium salinarum, Np Natronomonas pharaonis, BR bacteriorhodopsin, SR sensory rhodopsin, PR proteorhodopsin, NR Neurospora rhodopsin, CSRA and CSRB Chlamydomonas sensory rhodopsins A and B) Conserved residues are marked with black boxes, and residues in the retinal-binding pocket are marked with an asterisk. 

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