N-terminal is blocked by acetylation.
FUNCTION: PRODUCES PENTOSE SUGARS FOR NUCLEIC ACID SYNTHESIS AND MAIN PRODUCER OF NADPH REDUCING POWER.
* CATALYTIC ACTIVITY: D-glucose 6-phosphate + NADP+ = D-glucono-1,5-lactone 6-phosphate + NADPH.
* PATHWAY: Pentose phosphate pathway; first step.
* SUBUNIT: HOMODIMER OR HOMOTETRAMER.
* ALTERNATIVE PRODUCTS: 2 isoforms; a long form and short form (shown here); are produced by alternative splicing.
* TISSUE SPECIFICITY: The long isoform is found in lymphoblasts, granulocytes and sperm.
* POLYMORPHISM: THE SEQUENCE SHOWN IS THAT OF VARIANT B, THE MOST COMMON VARIANT.
* DISEASE: THE RED BLOOD CELLS OF INDIVIDUALS WITH DEFECTIVE OR INACTIVE GD TEND TO UNDERGO HEMOLYSIS (THE LOSS OF HEMOGLOBIN THROUGH THE DAMAGED MEMBRANE) CAUSING ANEMIA. DEFICIENCY OF G6PD IS ASSOCIATED WITH HEMOLYTIC ANEMIA IN TWO DIFFERENT SITUATIONS. FIRST, IN AREAS IN WHICH MALARIA HAS BEEN ENDEMIC, G6PD-DEFICIENCY ALLELES HAVE REACHED HIGH FREQUENCIES (1% TO 50%) AND DEFICIENT INDIVIDUALS, THOUGH ESSENTIALLY ASYMPTOMATIC IN THE STEADY STATE, HAVE A HIGH RISK OF ACUTE HEMOLYTIC ATTACKS. SECONDLY, SPORADIC CASES OF G6PD DEFICIENCY OCCUR AT A VERY LOW FREQUENCIES, AND THEY USUALLY PRESENT A MORE SEVERE PHENOTYPE, NAMELY CHRONIC NONSPHEROCYTIC HEMOLYTIC ANEMIA (CNSHA). THEY ARE DIVIDED IN SEVERAL TYPES. CLASS-I VARIANTS ARE ASSOCIATED WITH SEVERE CNSHA; CLASS-II HAVE AN ACTIVITY <10% OF NORMAL; CLASS-III HAVE AN ACTIVITY OF 10% TO 60% OF NORMAL; CLASS-IV HAVE NEAR NORMAL ACTIVITY.
* SIMILARITY: BELONGS TO THE GLUCOSE-6-PHOSPHATE DEHYDROGENASE FAMILY.
* DATABASE: NAME=G6PD; NOTE=G6PD deficiency resource; WWW="http://rialto.com/g6pd/".
* DATABASE: NAME=G6PDdb; NOTE=G6PD mutation database; WWW="http://www.rubic.rdg.ac.uk/g6pd/".
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