Sequence analysis of MLH1 protein

- To search protein file in SWISS-PROT Database
- To use analysis tools in ExPASy

1. Search human MutL protein homolog 1, Mlh1, in SWISS-PROT database. Give its (a) accession number, (b) entry name and (c) release date of last modification.

answer: (link)

(a) accession number: P40692 (b)entry name: MLH1_HUMAN (c)release date of last modification: Sequence was last modified in Release 31, February 1995 ; Annotations were last modified in Release 40, October 2001

2. Give its number of amino acids, molecular weight and theoretical pI.

answer: the number of amino acids: 756 ; molecular weight: 84600.9 ; theoretical pI: 5.51

3. Calculate the total number of negatively charged residues and positively charged residues.

answer: Total number of negatively charged residues (Asp + Glu): 104
            Total number of positively charged residues (Arg + Lys): 83

4. Calculate its hydrophobicity (Kyte & Doolittle scale, window size 11, Relative weight 60%).

answer: (link)

Ala: 1.800 Arg: -4.500 Asn: -3.500 Asp: -3.500 Cys: 2.500 Gln: -3.500
Glu: -3.500 Gly: -0.400 His: -3.200 Ile: 4.500 Leu: 3.800 Lys: -3.900
Met: 1.900 Phe: 2.800 Pro: -1.600 Ser: -0.800 Thr: -0.700 Trp: -0.900
Tyr: -1.300 Val: 4.200 Asx: -3.500 Glx: -3.500 Xaa: -0.490

5. Performe the trypsin (higher specificity) cleavage of the protein. (a) How many peptides will you get after cleavage? (b) Give the list of peptides with a mass bigger than 1000 dalton.

answer: (link)

(a)33

(b)answer