How to reproduce this specific sequence logo from 10 000 human mRNAs? this is A sequence logo showing the most conserved bases around the initiation codon from 10000 human mRNAs.



I would like to reproduce this sequence logo. How can I get the sequences? which database should I use? 

this search is apparently wrong, since I don't know the right way.

https://www.ncbi.nlm.nih.gov/nuccore/?term=10000+human+mRNAs
If you look at the Appendix from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC306349/, there is a table of sequences that were likely used to construct the sequence logo, at least partially, from the 5' end to the stereotyped ATG subsequence.

It's not in a nice format amenable to use directly with weblogo (like FASTA), but with some programming/elbow grease it might be rendered into that form, which you can then use.

Generally, you might investigate the supplementary materials of these and related papers, to see if you might something directly usable.