slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Nucleotide biosynthesis PowerPoint Presentation
Download Presentation
Nucleotide biosynthesis

Loading in 2 Seconds...

play fullscreen
1 / 14

Nucleotide biosynthesis - PowerPoint PPT Presentation


  • 209 Views
  • Uploaded on

Nucleotide biosynthesis. Base Nucleoside Nucleotide (base + ribose) (nucleoside + phosphate) A denine A denosine AMP (adenylic acid or adenosine monophosphate) G uanine G uanosine GMP (guanylic acid

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Nucleotide biosynthesis' - omer


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Nucleotide biosynthesis

BaseNucleoside Nucleotide

(base + ribose) (nucleoside + phosphate)

Adenine Adenosine AMP (adenylic acid

or adenosine monophosphate)

Guanine Guanosine GMP (guanylic acid

or guanosine monophosphate)

Uracil Uridine UMP (uridylic acid

or uridine monophosphate)

Thymine Thymidine TMP (thymidylic acid

or thymidine monosphosphate)

Cytosine Cytidine CMP (cytidylic acid

or cytidine monophosphate)

slide2

The purine ring numbering system is:

Purines

Adenine is 6-aminopurine.

Guanine is 2-amino-6-oxopurine.

slide3

Purine biosynthesis was investigated by John Buchanan

(University of Pennsylvania and MIT) and

Robert Greenberg (University of Michigan) in the 1940s.

Buchanan fed labelled precursors to pigeons and analysed

their incorporation into urate.

Birds excrete excess nitrogen

as urate (a purine).

slide4

The sequence of precursors that contribute ring atoms is:

Glutamine Glycine Formyl-THF Glutamine CO2 Aspartate Formyl-THF

All contribute one ring atom except glycine which contributes 3.

The purine ring is built up on a ribose sugar that is derived

fromPRPP.

slide5

6

5

7

N

N

1

8

2

N

N

4

9

3

The order in which ring atoms are added is:

9 4 5 7 8 3 6 1 2

Q G For Q CO2 D For

Ribose-P

slide6

Azaserine is a toxic analogue of glutamine that inhibits purine

biosynthesis.

Glutamine

Azaserine

Sulfonamide antibiotics inhibit folate biosynthesis and block

purine biosynthesis.

They cause bacteria to accumulate a biosynthetic intermediate.

slide10

Q G For Q CO2 D For

9 4 5 7 8 3 6 1 2

Q 9

G 457

For 8

Q 3

CO2 6

D 1

For 2

slide11

Four ATP molecules are used up during construction

of each IMP,mostly for activation steps.

The intermediate 5-amino imidazole 4-carboxamide ribonucleotide

is equivalent to the remains of AMP after the N1-C2 fragment is

used for HIS biosynthesis.

slide13

Glutamine is the source of amino groups for conversion

of XMP to GMP.

GTP is required for conversion of IMP to AMP.

ATP is required for conversion of IMP to GMP.

This helps to balance the concentrations of AMP and GMP

in cells.