求解practice book 上的两个题

hughzlUID: 201205

60. When the coding region of a prokayotic gene is cloned into the lacZ gene downstream from the translational initiator, the chance of an in-frame fusion is
A 1/2
B 1/3
C 1/5
D 1/6
E 1/9
in-frame fusion 到底是什么东西啊？没见过

93. Which of the following pairs of compounds are interconvertible in the liver by a sigle polypeptide chain containing two different catalytic sites?
A Glucose and glucose 6-phosphate
B 3-phosphoglycerate and phosphoenolpyruvate
C Phosphoenolpyruvate and pyruvate
D Fructose 6-phosphate and frutose 1,6-bisphosphate
E Fructose 6-phosphate and frutose 2,6-bisphosphate
又没见过！居然选E

谢谢

scapegoatUID: 205003

in-frame fusion 应该是指符合阅读框的插入。插入后要考虑到可以正确转录，需要保证插入序列的转录方向问题，即5’，3’的顺序一致性，还有密码子的阅读问题。 而这两者间是独立事件，所以概率是1/2*1/3=1/6

至于Fructose 6-phosphate and frutose 2,6-bisphosphate，是这样的。PFK-2 is bi-functional。具有PFK2活性和F26BPase活性。在ATP条件下催化F6P为F26BP，同时，在PKA和ATP条件下，PFK2这个酶被磷酸化，F26BPase活性被激活，催化F26BP成为F6P。

hughzlUID: 201205

非常谢谢
ETS考得真偏