leotides with rabbit aldolase A and B was detected. The binding of nucleotides to both isozymes is ba- sed on multipoint interactions. Phosphate moiety.
THURSDAY 2 APRIL
POSTERS RELATED TO S31 Th ~ S1-28 3
Thu-S31-29
MOLECULAR PROPERTIES OF THE RIBOSOMAL RNAs FROM Artemia LARVAE JesCls C w e s , Jesus Sebastian and Jaime Renart Instituto de Enzimologia, CSIC. Fac de Medicina, Universidad Autonoma. Madrid 34. Spain Ribosomal RNAS (rRNAs) from larvae of the crustacean Artemia behave in sucrose gradients and polyacrylamide gel electrophoresis under native conditions as 5 S, 17 S and 25 S. However, when studied under denaturing conditions, the 25 S rrWA component dissapears giving rise to three fragments of 120, 1880 and 2060 bases. The fact that the disaggregation takes place under a variety of conditions (formamide, urea, glyoxal and heating) strongly suggests that the 25 S rRNA is composed of three subunits, held together by hydrogen bonding. The sizes of the larger rWs from Artemia larvae are: 1.91 kb for the 17 S and 3.94 kb for the 25 S complex. The existence of a hidden break in the 25 S complex from Artemia is consistent with the hypothesis that this property is a general feature of lower eukaryotes rQNAs.
CHARACTFNZATI(X? OF EIGHT ALU FAMILY REPETITIVE SEQUENCES NE&R THE MIMBTJ GLOBIN G m . A. A. S l a t e r , 0. J. Grindlay, K. Vass, M. A. S t i n s o n and J. Paul Beatson Institute f o r Gncer Research, Oarscube E s t a t e , Bearsden, Glasgow, C61 lBD, Scotland. Eight members of t h e & interspersed repeat family which a r e present i n the intergene regions of the human P-type g l o b i n gene cluster have been c h a r a c t e r i z e d by e l e c t r o n microscope and restricThe o r d e r of the tion endonuclease mapping. human P-type g l o b i n genes i s 5'- y62- 6.07-AY-w 16-!3-3'. Three pairs of i n v e r t e d repeat sequences with t h e same relative o r i e n t s t i o n s are found. Qle pair occurs 5' t o t h e 6 - g l o b i n gene, one 5' t o the S - g l o b i n gene and a n o t h e r pair t o the 3' s i d e of t h e P-globin gene. Two single repetitive sequences are found, 5' t o t h e Gy- and YPl-globin genes respectively. These sequences and those imnediately 5' t o the 4- and 6-globin genes have t h e same orientation. In heterodupleres, the lengths of t h e repetitive sequences are between 220 and 300 base pairs.
Th~S31-31 MODE OF INTERACTION OF NUCLEOTIDES WITH RABBIT iYlUSCLE AND RABBIT LIVER ALDOLASE Marian KOCK4AN and l'laria T.IIAS D i v i s i o n of Biochem., Inst. of Organic k Physical Chemistry. Technical University, Wroclaw, Poland. The comparison o f mononucleotides-induced d i f f e r ence s p e c t r a with those produced by P i , PPi, PPPi and R-5-P allowed t o d i s s e c t c o n t r i b u t i o n o f phosp h a t e and purine moieties of nucleotides bound t o t h e enzymes. D i s t i n c t mode of i n t e r a c t i o n of nucl e o t i d e s with r a b b i t a l d o l a s e A and B was detected. The binding of n u c l e o t i d e s t o both isozymes is bas e d on m u l t i p o i n t i n t e r a c t i o n s . Phosphate moiety i n t e r a c t i o n causes p e r t u r b a t i o n of microenvironment of p r o t e i n t y r o s i n e and tryptophan r e s i d u e s . Adenine moiety i n t e r a c t i o n presumably involves hydrogen bonding formation between N-7 and/or N-1 atom and s i d e c h a i n of l y s i n e , a r g i n i n e , o r tyroThe above experiments suggest a n e x i s t e n c e sine o f s p e c i f i c nucleotide binding doinain i n a l d o l a s e molecule and may i n d i c a t e t h a t a l d o l a s e is t h e prcarc& 3Fo$&Y$Fgent e v o l u t i o n from a nucleotide bin-
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DOUBLE HYPERPRODUCING D-SWINE DEAMINASE AND 1-GAWCTOSIDASE MUTANT OF E. COLI
PavlasovA E., S t e j s k a l o v d E., S i k y t a B. I n s t i t u t e o f Microbiology, Czechoslovak Academy o f S c i e n c e s , 142 20 Prague 4 , Czechoslovakia Hyperproducing mutant was s e l e c t e d by a chemostat method u s i n g two s u c c e s s i v e sel e c t i o n processes. The s e l e c t i o n p r e s s u r e i n t h e first process by n i t r o g e n limitat i o n , i n t h e second one by carbon l i m i t a t i o n was caused, I n t h e first s e l e c t i o n a c o n s t i t u t i v e hyperproducing D-serine deaminase mutant was obtained. The r e s u l t i n g mutant o f t h e second one was the c o n s t i t u t i v e double hyperproducing D-serine deamlnase and p-galactosidase mutant. The spec i f i c a c t i v i t y of D-serine deaminase is 1 6 f o l d and P-galactosidase 6 f o l d higher i n comparison wi'th t h e f u l l y induced inducible parental strain.
Thu-S31-33 ISOALLELE POLYMORPHISM OF PINUS NIGRA IN THE NATIVE REGION OF ITS DISTRIBUTION. Djordj e Nikol i c Maize Res. I n s t . Zemun 11081, Yugoslavia.
I t has been i n v e s t i g a t e d i s o a l l e l e polymorphism i n Pinus n i g r a by t h e gene markers c o n t r o l l i n g the s y n t h e s i s o f e s t e r a s e (EST), leucinaminopeptidase (LAP) and a c i d phosphatase (APH) enzymes. I n t h e s e study i t was used t h e haploid endosperm o f r i p e seed c o l l e c t e d from i n d i v i d u a l t r e e s l o c a t e d i n 28 stands. By zonal e l e c t r o p h o r e t i c s e p a r a t i o n o f E. niRra haploid endosperm i t has been determined: degree o f polymorphism (P), average number of a l l e l e s per l o c i (A/L) average heterozygosity (He) and g e n e t i c d i s t a n c e between populations (Do).
Human enzymes and o t h e r p r o t e i n s determined by m u l t i p l e gene l o c i . EDWARDS, Y.H. and HOPKINSON, D.A. MRC Human Biochemical Genetics Unit, Galton Laboratory, University College London. Bearing i n mind t h e c u r r e n t i n t e r e s t i n gene c l u s t e r s , t h e i r r e g u l a t i o n and the incidence of i n d i v i d u a l v a r i a t i o n i n nucleotide sequence i n and around t h e s e l o c i , we have compiled d a t a about those human enzymes and p r o t e i n s d e t e r mined a t m u l t i p l e gene l o c i . There i s evidence t h a t t h e s e l o c i a r o s e by gene d u p l i c a t i o n but do n o t , i n g e n e r a l , occur i n linked groups on chromosomes. The incidence of v a r i a t i o n , presumably due t o s i n g l e n u c l e o t i d e s u b s t i t u t i q w i t h i n t h e coding region of t h e s e genes appears t o be a t l e a s t t e n f o l d l e s s than p o i n t mutation i n t h e i n t e r v e n i n g and f l a n k i n g sequences of t h e globin c l u s t e r and i s r e l a t e d t o t h e s t r u c t u r a l f e a t u r e s of t h e polypeptide product.
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