PspA adopts an ESCRT-III-like fold and remodels bacterial membranes

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Primary Amoebic Meningoencephalitis in Britain

Meningoencephalitis proved to be due to an amoeba (Naegleria) has been diagnosed in Great Britain for the first time. The first patient (a boy of 2) survived longer than any previously recorded cases, but in spite of early diagnosis and treatment he died 15 days after the onset of meningeal symptoms.Two other children who were exposed to the same possible source of infection (a warm, muddy puddle) had similar symptoms and developed mild meningitis. A naegleria was isolated from the cerebrospinal fluid of one of them. Both recovered after treatment with amphotericin.     

Rapid degradation of D- and L-succinimide-containing peptides by a post-proline endopeptidase from human erythrocytes

We have been interested in the metabolic fate of proteins containing aspartyl succinimide (Asu) residues. These residues can be derived from the spontaneous rearrangement of Asp and Asn residues and from the spontaneous demethylation of enzymatically methylated L-isoAsp and D-Asp residues. Incubation of the synthetic hexapeptide N-Ac-Val-Tyr-Pro-Asu-Gly-Ala with the cytosolic fraction of human erythrocytes resulted in rapid cleavage of the prolyl-aspartyl succinimide bond producing the tripeptide N-Ac-Val-Tyr-Pro. The rate of this reaction is equal for both L- and D-Asu-containing peptides and is 10-fold greater than the rate of cleavage of a corresponding peptide containing a normal Pro-Asp linkage. When the aspartyl succinimide ring was replaced with an isoaspartyl residue, the cleavage rate was about 5 times that of the normal Pro-Asp peptide. The tripeptide-producing activity copurified on DEAE-cellulose chromatography with an activity that cleaves N-carbobenzoxy-Gly-Pro-4-methylcoumarin-7-amide, a post-proline endopeptidase substrate. These two activities were both inhibited by an antiserum to rat brain post-proline endopeptidase, and it appears that they are catalyzed by the same enzyme. This enzyme has a molecular weight of approximately 80,000 and is covalently labeled and inhibited by [3H]diisopropyl fluorophosphate. The facile cleavage of the succinimide- and isoaspartyl-containing peptides by this post-proline endopeptidase suggests that it may play a role in the metabolism of peptides containing altered aspartyl residues.     

Identification of the uvrB gene product

We have constructed plasmids carrying various restriction fragments of the biouvrB region of the Escherichia coli chromosome. By analyzing the proteins synthesized in maxicells from the uvrB⁺ plasmid pDR1494, and its derivatives containing γδ sequences inserted in the uvrB gene, we have determined that the uvrB gene is about two kilobase-pairs in length, that it is transcribed clockwise on the standard E. coli genetic map, and that it codes for a single polypeptide of M_r = 84,000. The number of uvrB polypeptides in a normal cell is estimated to be about 140.We have also found that the uvrB gene is cut by EcoRI near its promoter.     

Patterns of sexual behavior in male macaques

One large social group of each of three species of macaques (Macaca mulatta, M. fascicularis, M. radiata), housed in half-acre field cages at the California Primate Research Center, were observed for a total of 150 h. Data on sexual behavior and dominance interactions were recorded by pairs of experienced observers using a focal animal technique. Single or multiple mount-to-ejaculation sequences, number of thrusts per mount, number of mounts per sequence, duration of mounts per sequence, duration of sequences, social rank and frequency of sexual activity were recorded for each adult male. M. mulatta used a multiple mount-to-ejaculation (MME) pattern in 91% of their copulations. M. radiata used a single mount-to-ejaculation (SME) pattern in 91% of their copulations. M. fascicularis used both patterns—53% MME and 47% SME. A positive correlation was found between rank and sexual activity in fascicularis and mulatta males. A negative correlation between rank and sexual activity was found in radiata males and also a positive correlation between rank and age indicating that the youngest and most subordinate radiata males were the most sexually active males. In reviewing the literature, a relationship between degree of intermale competition, intermale tolerance and type of mounting pattern was revealed. Macaque species that primarily use an SME pattern also show sa high degree of intermale tolerance and little interrnale competition. Macaque species that primarily use an MME pattern typically show a high degree of intermale competition and a low degree of intermale tolerance. Possible events leading to such relationships are discussed.